This opinion was
yFTTEV
^ IN CLERKS OFFICE N
filed for record
at^&fliori 3-A\ ^
:OOUm;8WrEOFWASH(NQTOM
DATE
i 2 ] Susan L. Carlson
Supreme Court Clerk
GtUBPJUSriCB
IN THE SUPREME COURT OF THE STATE OF WASHINGTON
L.M., a minor, by and through his Guardian NO. 95173-0
ad Litem WILLIAM L.E. DUSSAULT,
Petitioner,
EN BANC
V.
LAURA HAMILTON,individually and her
marital community; LAURA HAMILTON Filed MAR 2 I 2019
LICENSED MIDWIFE, a Washington
business.
Respondents.
GORDON McCLOUD, J.—L.M. suffered a severe injury during birth and
subsequently sued Laura Hamilton, the midwife who delivered him, for negligence.
Hamilton prevailed at trial. L.M. now argues that the trial court erred by admitting
evidence that natural forces of labor could have caused the injury and testimony from a
biomechanical engineer to the same effect. L.M. argues that the trial court should have
excluded the evidence under Frye^ and the testimony under ER 702.^
'Frye v. United States, 54 App. D.C. 46, 293 F. 1013 (1923).
^ ER 702 provides: "If scientific, technical, or other specialized knowledge will
assist the trier of fact to understand the evidence or to determine a fact in issue, a witness
qualified as an expert by knowledge, skill, experience, training, or education, may testify
thereto in the form of an opinion or otherwise."
L.M. V. Hamilton, No. 95173-0
We affirm. Under Frye, the trial court must exclude evidence that is not based on
generally accepted science. Anderson v. Akzo Nobel Coatings, Inc., Ill Wn.2d 593, 603,
260 P.3d 857 (2011). And under ER 702, the trial court must exclude testimony from
unqualified experts and testimony that is unhelpful to the jury. Lakey v. Puget Sound
Energy, Inc., 176 Wn.2d 909, 918, 296 P.3d 860 (2013). Testimony is unhelpful to the
jury if it is unreliable, id., or lacks an adequate foundation,Johnston-Forbes v. Matsunaga,
181 Wn.2d 346, 357, 333 P.3d 388 (2014).
L.M.'s Frye challenge concerns the extent to which the challenged science must be
generally accepted. And his ER 702 challenge hinges on the amount of discretion an
appellate court grants a trial court under that rule. But before we resolve either issue, we
must explore the current state ofthe challenged science because we review Frye challenges
de novo. We must also detail what the trial court did because we review ER 702 challenges
for abuse of discretion.
Factual and Procedural Background
1. L.M. was injured during birth and subsequently sued the delivering midwife
On April 4, 2010, Laura Hamilton, a midwife, delivered L.M. Ex. 2 (medical
records) at 7; see also Clerk's Papers (CP) at 1586. Her notes from the procedure show
that she performed an "assisted shoulder delivery" and that L.M.'s right arm was "weak at
side." Ex. 2 at 7; see also CP at 1586-87.
In his first few months of life, L.M. experienced "complete paralysis" of his upper
arm, along with wealoiess of the entire arm. CP at 1567. In August 2010, exploratory
surgery to address the problem revealed substantial injuries to L.M.'s brachial plexus. Id.
L.M. V. Hamilton, No. 95173-0
The brachial plexus delivers signals from the spinal cord to the arm through a network of
nerves. CP at 1569. These nerves can suffer various injuries, the most severe of which are
avulsions(where the nerve is torn away from the spinal cord) and ruptures(where the nerve
is ripped apart). Id. Although most brachial plexus injuries (BPls) heal in six months,
avulsions and ruptures are permanent. CP at 1570; Verbatim Report ofProceedings(VRP)
(Oct. 28, 2015) at 27-28 (Test, of Robert DeMott, MD).
L.M.'s BPI is most likely permanent. CP at 1568, 1590. All five of his brachial
nerve roots were injured: two were ruptured, one was avulsed, and two were partially
avulsed. CP at 1587. To this day, he has limited use of his arm and experiences pain. CP
at 1665-68, 1671.
L.M., through his guardian ad litem, sued Hamilton. CP at 1453-58, 1395-1401.
He alleged that Hamilton responded negligently to his shoulder dystocia, an emergency in
which a baby's shoulder gets stuck during labor. CP at 1556-57, 1573, 1587-90. L.M.
claimed that Hamilton used excessive force, or traction, in her effort to free the shoulder.
Id. He claimed that only excessive traction—and not natural forces of labor (NFOL)—
could have caused his ruptures and avulsions. Id.
Hamilton argued that she properly delivered L.M. and that NFOL can and did cause
L.M.'s BPI. CP at 1848, 2652-53, 2660, 2663-65. She argued that L.M. did not experience
shoulder dystocia. VRP (Oct. 23, 2015) at 16 (Test, of Laura Hamilton). To support her
defense, Hamilton offered the testimony of several experts, including Dr. Allan Tencer, a
biomechanical engineer. CP at 1518-24.
L.M. V. Hamilton, No. 95173-0
2. The trial court denied L.M.'s motion to exclude NFOL evidence
A. L.M. moved to exclude NFOL evidence
Before trial, L.M. moved to exclude evidence of the NFOL theory as not generally
accepted under Frye and not helpful to the trier of fact under ER 702. CP at 1459-60.
According to L.M.,the relevant scientific community does not generally accept that NFOL
can cause "permanent, severe brachial plexus nerve avulsion and rupture," CP at 1482
(boldface omitted), and any suggestion to the contrary is too speculative to be admissible,
CP at 1473. L.M. drew support for his argument from two recent New York cases
excluding NFOL evidence. CP at 1475-79 (citing Muhammad v. Fitzpatrick, 91 A.D.3d
1353, 937 N.Y.S.2d 519 (App. Div. 2012); Nobre ex rel. Ferraro v. Shanahan, 42 Misc.
3d 909, 976 N.Y.S.2d 841 (Sup. Ct. 2013)).
He also relied on deposition testimony or declarations from three experts. Dr.
Howard Mandel, an obstetrician-gynecologist, stated that "an avulsion or rupture of
brachial plexus nerve roots to an otherwise normal baby cannot occur from mere uterine
contractions or maternal pushing, the so-called 'forces of nature,' and there are no medical
studies or case reports to support that contention." CP at 1590; see also CP at 1510("You
can't get avulsion from stretch. It's just physiologically impossible.").^ Dr. Mandel
^ Dr. Mandel cited a publication in which Dr. Michael S. Kreitzer argues that'"there
is no direct evidence to support the assumption that [NFOL] can cause permanent injury
due to rupture or avulsion.'" CP at 1590-91 (quoting JAMES A. O'Leary, Shoulder
Dystocia and Birth Injury Prevention and Treatment 202(3d ed. 2010)); see also
CP at 1516-17 (making same argument in a letter to an editor). At trial, however. Dr.
Mandel conceded that NFOL can cause permanent BPIs. VRP (Oct. 21,2015)at 119(Test,
of Howard Mandel, MD)("I believe . . . you can have stretch from [NFOL]," and "[i]f you
have a bad stretch injury, the nerves can be permanently damaged.").
4
L.M. V. Hamilton, No. 95173-0
acknowledged that he had not "done any research on nerve avulsion or specific reading on
it in over ten years." CP at 1511. Instead, he relied on his "education, training, and
experience and all the reading [he had] ever done." Id.
Dr. Stephen Glass, a pediatric neurologist, stated that "[gjiven the character of
delivery and given the degree and extent of this severe plexus injury, it is improbable that
the 'natural forces' of labor and delivery were solely responsible." CP at 1567-68. He also
stated that "avulsion injuries are caused only by application of excessive manual traction
of the delivering provider while trying to alleviate the shoulder dystocia." CP at 1573. He
concluded, "There are no meaningful scientific studies that have measured the forces
necessary to cause a brachial plexus injury compared with the forces exerted by a laboring
mother." Id.'^
And Pamela Kelly, a certified midwife, said that in her 30 years of practice, she had
"never heard of nor read any medical literature that says avulsion and ruptures of the
brachial plexus nerve roots ofan otherwise normal newborn can occur by way ofthe natural
forces of nature." CP at 1557 (boldface omitted).
B. Hamilton opposed L.M.'s motion
Hamilton argued that the NFOL theory "is based on generally accepted scientific
methodologies, principles, and techniques that have been published in the medical and
scientific literature over the last 25 years." CP at 1737. She relied heavily on a survey of
^ At trial. Dr. Glass conceded that NFOL "probably can contribute to some plexus
injuries." VRP (Oct. 22, 2015) at 89 (Test, of Stephen Glass, MD). Dr. Glass also
acknowledged that the literature includes case reports of NFOL causing permanent BPIs.
Id. at 115.
L.M. V. Hamilton, No. 95173-0
the medical literature by Dr. Robert DeMott, an obstetrician-gynecologist. CP at 1738-50,
1839-49. That literature shows that NFOL can clearly cause BPI, but it does not describe
what types of BPI—avulsion, rupture, etc.—this includes. CP at 1842-43. The reason is
that the precise subcategory of permanent BPI can be determined only by surgical
intervention, and "not all children with permanent injury undergo surgery where the
diagnosis of which type is able to be made." CP at 1839; see also CP at 1842-43. Dr.
DeMott disagreed with L.M.'s framing of the issue as whether the current literature shows
that NFOL cause avulsions or ruptures; Dr. DeMott believed the issue should be framed as
whether the current literature shows that NFOL cause permanent injuries. CP at 1842-43.
In surveying the literature. Dr. DeMott discussed Williams Obstetrics,^ "one of the
preeminent textbooks on obstetrics." CP at 1839-40. He explained that the book reveals
the "evolution of the science" regarding NFOL and BPIs. CP at 1839. Although earlier
editions of the textbook suggest that BPIs usually result from excessive traction, newer
editions recognize that BPIs may also result from NFOL. CP at 1839, 1990, 1993. The
newest edition (at the time of trial) notes that "severe" BPIs "may also occur without . . .
shoulder dystocia." CP at 1999.
^ F. Gary Cunningham et al., Williams Obstetrics (21st ed. 2001); F. Gary
Cunningham et al., Williams Obstetrics(22d ed. 2005); F. Gary Cunningham et
AL., Williams Obstetrics (23d ed. 2010); F. Gary Cunningham et al., Williams
Obstetrics (24th ed. 2014).
L.M. V. Hamilton, No. 95173-0
Dr. DeMott also discussed the fourth edition of PRECIS: An Update to Obstetrics
& Gynecology: Obstetrics.^ CP at 1840-41. That book claims that older textbooks state,
"without evidence," that BPIs are caused by excessive traction "in the presence of shoulder
dystocia." CP at 2006. But "multiple lines of evidence" now suggest that most BPIs are
caused by something else. Id. The book notes that more than half of BPIs occur in
uncomplicated vaginal deliveries and "mathematic and computer-simulated models"
suggest that NFOL are "far greater" than clinician-applied traction. Id.
Dr. DeMott also referenced several other pieces of literature suggesting that NFOL
can cause permanent BPIs. See CP at 1843-49. For example, he cited a 2008 case report
published in the American Journal of Obstetrics & GynecologyJ CP at 1843, 2008-10.
That case report involved a mother who delivered a baby with one push and without
physician traction—"the only role the doctor played was to catch the baby before it went
off the table"—yet the baby suffered a permanent BPI. CP at 2009-10.
Finally, Dr. DeMott discussed a 2014 "comprehensive, retrospective" report from
the American College Of Obstetrics and Gynecologists(ACOG)titled Neonatal Brachial
Plexus Palsy (ACOG Report or Report).^ CP at 1841, 1867-1976. That report reflects
^ Am. Coll. of Obstetricians & Gynecologists, PRECIS: An Update in
Obstetrics & Gynecology: Obstetrics (4th ed. 2013).
'Henry Lerner, MD & Eva Salamon, MD, Permanent Brachial Plexus Injury
Following Vaginal Delivery without Physician Traction or Shoulder Dystocia, Am. J. of
Obstetrics & Gynecology, Mar. 2008, at e7-8.
^ Am. Coll. of Obstetricians & Gynecologists Task Force, Neonatal
Brachial Plexus Palsy (2014).
7
L.M. V. Hamilton, No. 95173-0
ACOG's review of published literature, ineluding original research, review articles, and
commentaries. CP at 1876. The underlying literature was reviewed for quality. Id. The
AGOG Report states.
The task force recognizes that knowledge about NBPP [neonatal
brachial plexus palsy or BPI] is continually evolving. What is known at this
time with reasonable medical certainty is that NBPP occurs infrequently and
can be caused by maternal (endogenous) forces or clinician-applied
(exogenous) forces or a combination of both. Similarly, NBPP can occur
with or without associated, clinically recognizable shoulder dystocia.
Finally, in the presence of shoulder dystocia, all intervention by way of
ancillary maneuvers—no matter how expertly performed—will necessarily
increase strain on the brachial plexus.
CP at 1882. The Report also shows that NFOL can cause permanent BPIs, noting that
injuries have "been shown to occur entirely unrelated to traction, with studies
demonstrating cases of both transient and persistent NBPP in fetuses delivered vaginally
without clinically evident shoulder dystocia or fetuses delivered by cesarean without
shoulder dystocia." CP at 1899; see also CP at 1910 ("No published clinical or
experimental data exist to support the contention that the presence of persistent (as
compared to transient) NBPP implies the application of excessive force by the birth
attendant."). The Report, however, notes that "more investigation" is necessary. CP at
1916.
The ACOG Report has been endorsed by several professional organizations,
including the American Academy ofPediatrics, the American College ofNurse-Midwives,
and the American Gynecological & Obstetrical Society. CP at 1878.^
^ It has also been endorsed by the American Academy of Physical Medicine and
Rehabilitation, the American Society for Reproductive Medicine, the Child Neurology
8
L.M. V. Hamilton, No. 95173-0
C. The trial court initially granted L.M.'s motion to exclude NFOL evidence
At first, the trial court granted L.M.'s motion. CP at 2622-26. The court held that
under ER 702,the NFOL theory was too speculative on causation because it fails to explain
how natural forces cause avulsions and ruptures. CP at 2289-91. The court also rejected
the NFOL theory under Frye, holding that the scientific community has not reached a
"consensus" on whether "the permanent avulsion injuries can be caused by natural forces."
CP at 2290 (excerpt of court's Sept. 18, 2015 oral ruling).
D. On reconsideration, the trial court admitted NFOL evidence
Hamilton moved for reconsideration. CP at 2920. She listed all the courts that had
previously allowed NFOL evidence. CP at 2938-46 (citing cases). She also filed additional
expert declarations. Dr. DeMott stated that a consensus of the relevant scientific
community now accepts "that [NFOL] can cause permanent [BPI], including brachial
nerve avulsion and rupture." CP at 2667-68. Dr. Elizabeth Sanford, another obstetrician-
gynecologist, stated that the obstetric community "agree[s] that permanent brachial plexus
injuries can be caused by [NFOL]" and that "[p]ermanent injuries include brachial plexus
Society, the Japan Society of Obstetrics and Gynecology, the Royal Australian and New
Zealand College of Obstetricians and Gynaecologists, the Society for Maternal-Fetal
Medicine, and the Society of Obstetricians and Gynaecologists of Canada. CP at 1878.
And the March of Dimes Foundation and the Royal College of Obstetricians and
Gynaecologists have offered their full support. Id.
L.M. V. Hamilton, No. 95173-0
ruptures and avulsions." CP at 2663."^ Dr. Thomas Collins, a neurologist, stated that
"[t]here is a general consensus in the medical community that permanent brachial plexus
injury can occur due to [NFOL]" and that "[tjhere is no specifically identified research
study that supports the contention that rupture and avulsion of nerves only occurs with
excessive traction." CP at 2674. Beth Coyote, a midwife, agreed. CP at 2652-53.
The trial court then reversed its prior ruling. CP at 3246-47. Regarding Frye, the
trial court noted that an expert's "ultimate opinion" on causation "does not have to be
generally accepted so long as [his or her]... opinions are based on accepted methodology."
VRP (Oct. 12, 2015) at 26 (motion hearing). That Frye standard, the trial court held, was
satisfied in this case. Id. at 29. RegardingER702,the trial court ruled that NFOL evidence
had sufficient foundation to be helpful to the jury. See id. at 27-30. It explained that any
gaps in the science result from appropriate "ethical considerations": researchers cannot
experiment on babies to determine the force required to cause an avulsion. Id. at 28-29."
Instead, researchers must rely on peer-reviewed and published literature. Id. at 29. That
literature shows that NFOL can cause severe BPIs. Id. at 27-30. The trial court held that
this is "sufficient to bridge that analytical gap between the natural forces theory and the
injury" and reach the jury. Id. at 29.
In an earlier declaration. Dr. Sanford had noted that the medical literature is
limited. CP at 1529("there's still quite a bit that we need to find out"), 1530("the literature
does not very specifically state" how NFOL cause permanent BPIs).
" At trial, Dr. Mandel, L.M.'s expert, elaborated on the ethical dilemma facing
researchers: it "would be criminal to cause avulsion just to prove a medical point." VRP
(Oct. 21, 2015) at 90 (Test, of Howard Mandel, MD). "Why would you want to hurt a
baby?" Id. at 91.
10
L.M. V, Hamilton, No. 95173-0
3. The trial court allowed Dr. Tencer to testily
The other pretrial issue before us is whether Dr. Tencer should have been allowed
to testily about the internal (endogenous) and external (exogenous) forces involved in
childbirth. CP at 2358, 2374-76. Dr. Tencer has testified approximately 250 times, but
mostly in eases involving car crashes. VRP (Oct. 27, 2015) at 9 (Test, of Allan Tencer,
PhD). Prior to this case, he had never testified in a case involving labor and delivery. Id.
He holds a doctorate in mechanical engineering, and until recently, he taught orthopedics
and sports medicine, as well as mechanical engineering, at the University of Washington.
CP at 2372-73. Dr. Tencer does not hold a medical degree. CP at 2380. Nor has he
received specialized training in the mechanics of childbirth. CP at 2372-73, 2380-81. He
has, however, researched the strength of the spinal cord and nerve roots. CP at 2373; see
flAo VRP (Oct. 27,2015)at 5-7(Test, of Allan Tencer,PhD). And to prepare for this case,
he studied the latest science on the biomeehanics of childbirth, including the ACOG
Report. CP at 2372-78; VRP (Oct. 12, 2015) at 31-32.
In his declaration. Dr. Tencer concluded that "[fjrom a biomechanical forces
perspective, it is not possible to differentiate whether the brachial plexus nerve damage
suffered by [L.M.] resulted from exogenous, endogenous or some combination of both
forces." CP at 2376. He reached this conclusion after reviewing the current science on the
forces, including NFOL, at play. CP at 2373-76.
L.M. opposed, arguing that Dr. Tencer, who "is not an obstetrician or a midwife,"
"is testifying far outside his expertise." CP at 3180. He also criticized Dr. Tencer's
proposed testimony as speculative and misleading because Dr. Tencer misinterpreted and
11
L.M. V. Hamilton, No. 95173-0
drew "hasty generalization[s]" from the underlying literature. CP at 3180-84. For
example, L.M. claimed that Dr. Tencer "proposes to testify regarding forces that his own
published sources say are not possible." CP at 3180.
The trial court ruled that Dr. Tencer could testify. VRP (Oct. 12, 2015) at 37-38.
The court found that he was qualified and that his testimony would help the jury understand
the forces at play, thus satisfying ER 702's prerequisites to admissibility. Id. at 37. And
it ruled that L.M. could challenge Dr. Tencer's interpretation of the underlying literature
through cross-examination. Id. But it barred Dr. Tencer from testifying about specific
causation in L.M.'s case. Id. at 34, 37. The court stated that if Dr. Tencer ignored this
limitation, it would "expect an immediate objection which will be sustained." Id. at 37-
38.'2
4. The jury found that Hamilton was not negligent, and L.M. now appeals
The jury found that Hamilton was not negligent. CP at 4814. L.M. appealed the
pretrial decisions to admit NFOL evidence and to allow Dr. Tencer to testify. CP at 4753.
The Court ofAppeals affirmed. L.M. v. Hamilton,200 Wn. App. 535,402 P.3d 870(2017).
We granted review and also affirm. L.M. v. Hamilton, 191 Wn.2d 1011 (2018).
Analysis
The courts serve the gatekeeping function of keeping out "unreliable, untested, or
junk science." Anderson, 172 Wn.2d at 606 (citing 5B KarlB. Tegland, Washington
At trial, defense counsel asked Dr. Tencer whether, in his opinion, NFOL can
"cause the rupture and avulsion of a brachial plexus." VRP (Oct. 27, 2015) at 22(Test, of
Allan Tencer, PhD). Dr. Tencer responded, "It certainly appears so." Id. Plaintiffs
counsel did not object. See id.
12
L.M. V. Hamilton, No. 95173-0
Practice: Evidence Law & Practice § 702.18, at 81 (5th ed. 2007)). L.M. now argues
that the trial court's decision to admit NFOL evidence violated Frye and its decision to
allow Dr. Tencer to testify violated ER 702. We must determine whether the trial court
properly discharged its gatekeeping function.
1. The NFOL theory is not based on novel science and thus does not violate Frye
A. This court reviews Frye issues de novo
We review the trial court's Frye ruling de novo. Lakey, 176 Wn.2d at 919 (citing
Anderson, 172 Wn.2d at 600). The court also reviews de novo a trial court's decision,
made outside of a Frye hearing, that the scientific community generally accepts the science
at issue and thus that no Fiye hearing is necessary. State v. Gregory, 158 Wn.2d 759, 830,
147 P.3d 1201 (2006), overruled on other grounds by State v. W.R., 181 Wn.2d 757, 336
P.3d 1134 (2014).'^
B. Frye does not bar Hamilton's expertsfrom opining that NFOL caused L.M.'s
avulsions and ruptures
Frye requires experts to base their conclusions on generally accepted science.
Anderson, 172 Wn.2d at 603. The relevant scientific community must generally accept
both '"the underlying theory'" and the "'techniques, experiments, or studies'" applying
Hamilton argues that L.M. waived his Frye challenge by failing to request a Frye
hearing below. While it is true that L.M. did not request an evidentiary hearing or in-court
testimony on the Frye issue, CP at 1460, L.M. made Frye arguments at the trial court,
including that the scientific community does not generally accept the NFOL theory, e.g.,
CP at 1475-83, 3221. And the trial court ultimately ruled on the Frye issue. VRP (Oct.
12, 2015) at 26-30. L.M. therefore preserved the issue. Cf. Johnston-Forbes, 181 Wn.2d
at 356 (holding that "'a party who fails to seek a Frye hearing below does not preserve this
evidentiary challenge for review'" {c[\xo\lmg Johnston-Forbes v. Matsunaga, 111 Wn. App.
402,408, 311 P.3d 1260 (2013)).
13
L.M. V. Hamilton, No. 95173-0
that theory. Id. (quoting State v. Riker, 123 Wn.2d 351, 359, 869 P.2d 43 (1994)). The
techniques, experiments, or studies must be '"capable of producing reliable results.'" Id.
(quoting Riker, 123 Wn.2d at 359). The scientific community does not have to be
unanimous; the court should exclude the expert's opinion only "'[i]f there is a significant
dispute among qualified scientists.'" Id. (internal quotation marks omitted) (quoting
Gregory, 158 Wn.2d at 829).
"[T]he application of accepted techniques to reach novel conclusions does not raise
Frye concerns." Lakey, 176 Wn.2d at 919. 'Hrye does not require every deduction drawn
from generally accepted theories to be generally accepted." Anderson, 172 Wn.2d at 611.
"Other evidentiary requirements provide additional protections from deductions that are
mere speculation." Id. (citing ER 104(a); ER 401; ER 403); see also id. at 603 ("'Once a
methodology is accepted in the scientific community, then application of the science to a
particular case is a matter of weight and admissibility under ER 702.'"(quoting Gregory,
158 Wn.2d at 829-30 (citing ER 702))).
For example, in Anderson, Julie Anderson gave birth to a son, who was later
diagnosed with various "medical abnormalities." Anderson, 172 Wn.2d at 598. A doctor
opined that the son's abnormalities were likely due to Anderson's exposure to paint at work
while she was pregnant. Id. An expert agreed with the doctor and was willing to testify
that the employer's paint caused the son's birth defects. Id.
The trial court excluded the expert's testimony under Frye because, at least at that
time, no member of the relevant scientific community had researched whether "the specific
type of organic solvents" in the employer's paint could cause "the specific type of birth
14
L.M. V. Hamilton, No. 95173-0
defects at issue." Id. at 605 (emphasis added). The trial court held that Frye requires a
"consensus of scientific opinion on the issue of specific causation." Id.
This court reversed. Id. We reiterated that trial courts should admit evidence under
Frye if the scientific community generally accepts the science underlying an expert's
conclusion; the scientifie community does not also have to generally accept the expert's
theory of specific causation. See id. at 609. It was sufficient for Anderson to "present[]
evidence that tended to show it is generally accepted by the seientific community that toxic
solvents like the ones to which Anderson was exposed . . . may damage the developing
brain of a fetus within the uterus." Id. at 610(emphasis added). Anderson did not have to
"establish that the specific causal connection between the specific toxic organic solvents
to which she was exposed and the specifie . . . birth defect is generally accepted." Id. at
611. Requiring "'general acceptance' of each discrete and ever more specific part of an
expert opinion" would place "virtually all opinions based upon scientifie data" into "some
part of the scientific twilight zone." Id. Because the court found nothing novel about the
science underlying the expert's testimony, it held that the testimony did not implicate Frye.
Id. at 611-12.
In this case, Hamilton argues that the scientific community generally accepts that
NFOL could have caused L.M.'s BPI. Although the literature is silent as to avulsions and
ruptures, she argues, it does say that NFOL can cause permanent BPIs. And because the
category of permanent BPIs includes avulsions and ruptures, Hamilton argues that NFOL
could have caused L.M.'s BPI.
15
L.M. V. Hamilton, No. 95173-0
Meanwhile, L.M. argues that the relevant scientific community does not generally
accept that NFOL can cause his specific BPI—rupture and avulsion at all five nerve roots.
He notes that the literature is silent as to whether NFOL can cause such a severe BPI.
Although L.M.'s own experts recognize that the literature suggests that NFOL can cause
permanent BPIs, they disagree over what types of permanent BPIs (e.g., severe stretching,
avulsions, ruptures) this includes.
Anderson resolves this dispute: ''Frye does not require every deduction drawn from
generally accepted theories to be generally aceepted." 172 Wn.2d at 611. For Frye
purposes, Hamilton does not have to prove that the relevant scientific community generally
accepts that NFOL could have caused L.M.'s ruptures and avulsions—much like Anderson
did not have to prove general acceptance of"the specific causal connection" in her case. It
is suffieient for Hamilton to draw such a deduction from generally accepted science. Here,
Hamilton's experts note that the science shows that NFOL can cause permanent BPIs.
From this they deduce that NFOL can cause avulsions and ruptures, both of which are types
of permanent BPIs. So long as the science underlying this deduction is generally accepted,
Frye is satisfied.
Requiring general acceptance of "each discrete and ever more specific part of an
expert opinion" (e.g., requiring general acceptance that NFOL can cause specific types of
permanent BPIs) would place "virtually all opinions based upon scientific data" into "some
part ofthe scientific twilight zone." Id. Other evidentiary rules—not Frye and not at issue
here—bar deductions that are too speculative.
16
L.M. V. Hamilton, No. 95173-0
In sum, Hamilton must show that her experts based their opinions on generally
accepted science.
C. Hamilton's experts based their opinions on generally accepted science
Hamilton's experts testified thatNFOL caused L.M.'s avulsions and ruptures. They
based this testimony on the underlying theory that NFOL can cause permanent BPIs and
on the literature surrounding that theory. To determine whether this satisfies Frye, we look
to "a number of sources," including the "record, available literature, and the cases of other
jurisdictions." State v. Baity, 140 Wn.2d 1, 10, 991 P.2d 1151 (2000) (citing State v.
Cauthron, 120 Wn.2d 879, 888, 846 P.2d 502 (1993)).
These sources reveal a generally accepted theory: NFOL can cause permanent BPIs.
This theory has developed from retrospective analyses of data and experiments that rely on
modeling, rather than on prospective experiments, because researchers cannot ethically
perform experiments on infants to determine exactly how much force causes the various
types of BPIs. Although the ethical limitations prevent researchers from performing some
studies, it does not follow that the studies they can perform are incapable of producing
reliable results. Nor does it matter, for Frye purposes, that more investigation and research
in the future will likely lead to even better results. What matters is that the theory is
generally accepted and that the techniques, experiments, and studies applying that theory
are also generally accepted and capable of producing reliable results. And that is clearly
the case here. The ACOG Report, for example, reviewed published literature, which was
reviewed for quality, and has been endorsed by several prominent organizations from
around the world.
17
L.M. V. Hamilton, No. 95173-0
L.M. fails to show that there is a significant dispute among scientists. In fact, L.M.'s
own experts recognize that the literature suggests that NFOL can cause permanent BPIs.
See VRP (Oct. 21, 2015) at 119 (Test, of Howard Mandel, MD); VRP (Oct. 22, 2015) at
115 (Test, of Stephen Glass, MD). Moreover, at the trial court, all ofL.M.'s cited literature
suggesting otherwise was authored by one person. Dr. Michael S. Kreitzer, and was
published before the ACOG Report. In his supplemental brief before this court, L.M. does
include two additional publications not authored by Dr. Kreitzer. Suppl. Br. ofPet'r at 15-
16. But neither publication reveals a significant dispute in the scientific community. In
fact, the first acknowledges that excessive traction is not the only possible cause of BPIs:
There is enough evidence that BPI can occur in the absence of shoulder
dystocia to conclude that not every injury is the consequence of excessive
force applied by the obstetrician or midwife. Moreover, it seems equally
clear that BPI can occur in association with shoulder dystocia even when the
complication has been managed optimally. The weight of the available
information suggests, however, that inopportune medical intervention is
probably a factor in most injuries.
Id. App. 1 at 001 (internal citations omitted). And the second appears to answer the Frye
inquiry in favor of Hamilton:"[Ajmong American obstetricians the idea that most injuries
develop 'in utero' spontaneously has gained wide acceptance.'" Id. App. 2 at 006 (second
emphasis added).
The author goes on to argue that American obstetricians favor the NFOL theory
because the "idea offers a firm ground for defending malpractice claims." Suppl. Br. of
Pet'r App. 2 at 006; see also Taber v. Roush, 316 S.W.3d 139, 180 (Tex. App. 2010)
(Anderson, J., dissenting)("I believe that much of[the literature] was motivated in no small
part by concerns over the amount of litigation involving brachial plexus injuries and the
lack of a viable defensive theory in the face of the only generally accepted cause of those
injuries: excessive traction by the delivering physician."). And L.M. notes that "[sjome of
the articles reference litigation as a consideration." Pet. for Review at 11.
18
L.M. V. Hamilton, No. 95173-0
Other jurisdictions agree. L.M. points us to only one court that has excluded NFOL
evidence in a BPI case under Frye. That court, from New York, affirmed a lower court's
holding that the NFOL theory is "a novel theory subject to a Frye analysis" and is "not
generally accepted within the relevant medical community." Muhammad, 91 A.D.Bd at
1354. But the court applied an abuse of discretion standard, rather than conduct de novo
review, and provided almost no reasoning. Id. And in a similar case, another New York
court distinguished Muhammad and held that defendants' NFOL theory satisfied the Frye
standard. Nobre, 42 Misc. 3d at 924-25.'^ There, the court reasoned that it could not
"conceive how a theory that has been studied, tested and debated for more than twenty
years can be deemed to be novel." Id. at 922.'® Other Frye jurisdictions have reached a
similar conclusion. E.g., Ruffin ex rel. Sanders v. Baler, 384 111. App. 3d 7, 22-25, 890
N.E.2d 1174,(2008).
But even if litigation motivated the science, it does not necessarily follow that the
scientists manipulated the techniques, experiments, or studies to reach a desired result.
Moreover, 10 professional organizations—from around the world—endorsed the 2014
ACOG Report. Finally, L.M. had every opportunity to draw out potential biases of the
cited medical literature during cross-examination of Hamilton's experts—and in fact did
so. E.g., VRP (Oct. 28, 2015) at 61-64 (Test, of Robert DeMott, MD).
The Nobre court distinguished Muhammad in part because Muhammad involved
"at least a partial avulsion," while Nobre involved "no rupture or avulsion." 42 Misc. 3d
at 924. But it also distinguished Muhammad because the Muhammad court conducted a
more limited review of the medical literature. Id. at 924-25.
'® The court in Nobre went on to exclude the theory for lack of foundation. Id. at
924-30.
19
LM. V. Hamilton, No. 95173-0
In sum, Hamilton's experts eoneluded that NFOL caused L.M.'s avulsions and
ruptures, and they based this conclusion on generally accepted science. Because Frye is
not implicated, we affirm the trial court's Frye determination to deny L.M.'s motion to
exclude evidence of the NFOL theory.
2. The trial court did not abuse its discretion by allowing Dr. Tencer to testify
"The trial court must exclude expert testimony involving scientific evidence unless
the testimony satisfies . . . ER 702." Lakey, 176 Wn.2d at 918 (citing State v. Copeland,
130 Wn.2d 244, 255-56, 922 P.2d 1304 (1996)). Expert testimony satisfies ER 702 if(1)
"the witness qualifies as an expert," and (2)"the testimony will assist the trier of fact." Id.
(citing Cauthron, 120 Wn.2d at 890 (citing ER 702)).'^
We review for abuse of discretion the trial court's admission of expert testimony
under ER 702. Lakey, 176 Wn.2d at 919 (citing State v. Yates, 161 Wn.2d 714, 762, 168
P.3d 359 (2007)). "A trial court abuses its discretion by issuing manifestly unreasonable
rulings or rulings based on untenable grounds, such as a ruling contrary to law." Id. (citing
Wash. State Physicians Ins. Exch. & Ass'n v. Fisons Corp., 122 Wn.2d 299, 339, 858 P.2d
1054 (1993)). A reviewing court may not hold that a trial court abused its discretion
In recent years, we have oeeasionally expressed a three-part test in which we also
require the expert to rely on generally accepted theories. Gilmore v. Jefferson County Pub.
Transp. Benefit Area, 190 Wn.2d 483, 495, 415 P.3d 212 (2018); Johnston-Forbes, 181
Wn.2d at 352; In re Pers. Restraint of Morris, 176 Wn.2d 157, 168-69, 288 P.3d 1140
(2012); In re Marriage of Katare, 175 Wn.2d 23, 38, 283 P.3d 546 (2012). But that
additional general acceptance part is really a Frye determination. "Because we review a
Frye determination de novo, but review issues under ER 702 only for abuse of discretion,
we find it inappropriate to include a Frye determination as part of the test for proper
admissibility of expert testimony under ER 702." Cauthron, 120 Wn.2d at 890 n.4.
20
L.M. V. Hamilton, No. 95173-0
"'simply because it would have decided the case differently.'" Gilmore v. Jefferson County
Pub. Transp. Benefit Area, 190 Wn.2d 483, 494, 415 P.3d 212 (2018)(quoting State v.
Salgado-Mendoza, 189 Wn.2d 420,427,403 P.3d 45(2017)). To find abuse of discretion,
a court "'must be convinced that'"no reasonable person would take the view adopted by
the trial court.""" Id. (emphasis added)(quoting Salgado-Mendoza, 189 Wn.2d at 427
(quoting State v. Perez-Cervantes, 141 Wn.2d 468,475,6 P.3d 1160(2000)(quoting State
V. Huelett, 92 Wn.2d 967, 969, 603 P.2d 1258 (1979)))). '"[I]f the basis for admission of
the evidence is fairly debatable,'" a court "'will not disturb the trial court's ruling.'" Id.
(internal quotations omitted)(quoting Grp. Health Coop, ofPuget Sound, Inc. v. Dep 't of
Revenue, 106 Wn.2d 391, 398, 722 P.2d 787(1986)).
A. The trial court did not abuse its discretion in ruling that Dr. Tencer was
qualified to testify
A witness may qualify as an expert "by knowledge, skill, experience, training, or
education." ER 702. "An expert may not testify about information outside his area of
expertise." In re Marriage ofKatare, 175 Wn.2d23,38,283 P.3d 546(2012)(citing Queen
City Farms, Inc. v. Cent. Nat'l Ins. Co. ofOmaha, 126 Wn.2d 50, 104, 882 P.2d 703, 891
P.2d 718 (1994)(plurality opinion)). When determining whether a witness is an expert,
courts should look beyond academic credentials. Harris v. Robert C. Groth, MD,Inc., 99
Wn.2d 438,449-50,663 P.2d 113(1983). For example, depending on the circumstance, a
nonphysician might be qualified to testify in a medical malpractice action. Id. '"[T]he line
between chemistry, biology, and medicine is too indefinite to admit of a practicable
separation of topics and witnesses.'" Id. at 450 (quoting 2 JOHN HENRY WiGMORE,
21
L.M. V. Hamilton, No. 95173-0
Evidence in Trials at Common Law § 569, at 790 (rev. 1979)). But when making the
determination, courts must consider whether the expert has '"sufficient expertise in the
relevant specialty.'" Frausto v. Yakima HMA, LLC, 188 Wn.2d 227, 232, 393 P.3d 776
(2017)(quoting Young v. Key Pharm., Inc., 112 Wn.2d216, 229, 770 P.2d 182(1989)).
Parties often call Dr. Teneer to testify as an expert, typically in eases involving
automobile collisions. Sometimes his testimony has been admissible, sometimes it has not.
In Stedman v. Cooper, for example, the trial court barred Dr. Teneer from testifying. 172
Wn. App. 9, 13, 292 P.3d 764(2012). Applying an abuse of discretion standard, the Court
of Appeals affirmed, holding that Dr. Teneer's "clear message was that Stedman could not
have been injured in the accident because the force of the impact was too small." Id. at 20.
In Ma'ele v. Arrington, in contrast, the trial court admitted Dr. Tencer's testimony. 111
Wn. App. 557, 560, 45 P.3d 557 (2002). Like in Stedman, Dr. Teneer "expressed no
opinion about Ma'ele's symptoms or possible diagnosis from those symptoms." Id. at 564.
Applying an abuse of discretion standard, the Court of Appeals affirmed, stating that the
jury was "entitled to infer" from Dr. Tencer's testimony that Ma'ele was injured in the
crash. Id. 563-64.
The apparent inconsistency between Stedman and Ma'ele is due to the abuse of
discretion standard. Johnston-Forbes, 181 Wn.2d at 353. '"The broad standard of abuse
of discretion means that courts can reasonably reach different conclusions about whether,
and to what extent, an expert's testimony will be helpful to the jury in a particular case.'"
Id. at 353-54(quoting Stedman, 172 Wn. App. at 18). The broad standard also means that
courts can reasonably reach different conclusions about whether an expert is qualified.
22
L.M. V. Hamilton, No. 95173-0
In this case, L.M. argues that Dr. Tencer was not qualified to testify at all because
he lacked expertise in the forces of childbirth. On the one hand, courts must determine
whether an expert has "sufficient expertise in the relevant specialty." Frausto, 188 Wn.2d
at 232. Dr. Tencer does not have remarkable expertise in the biomechanics of childbirth;
until his retirement, he taught orthopedics and sports medicine. But on the other hand, the
evidence rules say that a witness may qualify as an expert"by knowledge, skill, experience,
training, or education." ER 702 (emphasis added). Although Dr. Tencer is not specially
trained in the biomechanics of childbirth, he is highly qualified to testify about
biomechanical forces in general. He has also personally researched the spine. CP at 2372-
73. And to prepare for this case, he looked at the latest science regarding the biomechanics
of childbirth. Id. at 2372-78; VRP (Oct. 12, 2015) at 31-32. As the AGOG Report notes,
"biomechanics is a means through which the causes of[BPIs] have been and continue to
be investigated and understood." CP at 2424. Dr. Tencer, a biomechanical engineer, is
able to read the latest science, learn the forces at play, and apply that new knowledge to
what he already knows about the spine.
This is a close call. But "'[i]f the basis for admission of the evidence is fairly
debatable,'" a court'"will not disturb the trial court's ruling.'" Gilmore, 190 Wn.2d at 494
(internal quotation marks omitted)(quoting Grp. Health Coop., 106 Wn.2d at 398). The
trial court did not abuse its discretion in ruling that Dr. Tencer was qualified to provide
biomechanical testimony.
23
L.M. V. Hamilton, No. 95173-0
B. The trial court did not abuse its discretion in finding that Dr. fencer's
testimony was helpful to ajury
Courts find an expert's testimony to be helpful if it helps "the jury's understanding
of a matter outside the competence of an ordinary layperson." Reese v, Stroh, 128 Wn.2d
300,308, 907 P.2d 282(1995)(citing v. Ciskie, 110 Wn.2d 263, 279, 751 P.2d 1165
(1988); Riggins v. Bechtel Power Corp., 44 Wn. App 244, 254, 722 P.2d 819 (1986)).
"Unreliable testimony does not assist the trier of fact." Lakey, 176 Wn.2d at 918 (citing
Anderson, 172 Wn.2d at 600). Neither does testimony lacking an adequate foundation.
Johnston-Forbes, 181 Wn.2d at 357; Walker v. State, 121 Wn.2d 214, 218, 848 P.2d 721
(1993). "It is the proper function of the trial court to scrutinize the expert's underlying
information and determine whether it is sufficient to form an opinion on the relevant issue."
Johnston-Forbes, 181 Wn.2dat357.
Quantifying the forces of labor is obviously outside the competence of an ordinary
layperson. Instead, L.M. argues that Dr. Tencer used data inappropriately to reach a
preordained conclusion. Pet. for Review at 17. L.M. takes issue with Dr. Tencer's
testimony regarding the force necessary to injure the brachial plexus because "virtually all
the medical literature states that this force is not known and cannot be known,"Id. at 2; see
also id. at 18. But that force is difficult or even impossible to know in large part because
of ethical considerations, and the trial court was aware of this. VRP (Oct. 12, 2015) at 28-
29. Although the ethical considerations leave an analytical gap in the science, the trial
court found the analytical gap satisfactorily "bridge[d]" by the current literature showing
that NFOL can cause permanent BPIs. Id. at 29. The trial court ruled that any concerns
24
L.M. V. Hamilton, No. 95173-0
over Dr. Tencer's use of the data and any other concerns over the literature would make
"excellent arguments for cross-examination." Id. at 37.
The trial court's thoughtful review of the helpfulness prong was not manifestly
unreasonable and thus was not an abuse of discretion.
Conclusion
We affirm the trial court and hold that (1) it correctly admitted NFOL evidence
under Frye and (2) it did not abuse its discretion by allowing Dr. Tencer to testify.
25
L.M. V. Hamilton, No. 95173-0
WE CONCUR:
^t\AA , 0^
J / P.
26
LM. V. Hamilton
No. 95173-0
GonzAlez, J.(concurring in result only)—Allan Tencer, PhD,should not
have testified in this case. The trial court committed error in allowing him to
testify. I respectfully disagree with the majority's assertion that this is a close call.
However, because I believe that the error was ultimately harmless, I concur.
Tencer is not qualified to testify about the forces involved in childbirth. See
In re Marriage ofKatare, 175 Wn.2d 23, 38, 283 P.3d 546(2012)("An expert
may not testify about information outside his area of expertise." (citing Queen City
Farms, Inc. v. Cent. Nat'l Ins. Co. of Omaha, 126 Wn.2d 50, 104, 882 P.2d 703,
891 P.2d 718 (1994)(plurality opinion))). Tencer is a biomechanical engineer
with a background in the forces involved in automobile accidents and the effect
such forces may have on the human body. While it may not be error to admit his
expert testimony in automobile accident cases, it is error under these facts.
Compare Johnston-Forbes v. Matsunaga, 181 Wn.2d 346, 355, 333 P.3d 388
(2014)(affirming the limited admission of Tencer's testimony in an automobile
accident case), with Gilmore v. Jefferson County Pub. Trans. Benefit Area, 190
Wn.2d 483, 498, 415 P.3d 212(2018)(affirming the exclusion of Tencer's
LM. V. Hamilton, No. 95173-0 (Gonzalez, J., concurring in result only)
testimony in an automobile accident case because "it would create unreasonable
inferences, and confuse and mislead the jury").
The majority appears to accept that being a biomechanical engineer qualifies
Tencer to abstractly discuss the forces involved in childbirth. But finding that an
expert is qualified requires more than a highly educated person's cursory review of
relevant data; "'[t]he scope of the expert's knowledge'" governs. Frausto v.
YakimaHMA, LLC, 188 Wn.2d 227, 234, 393 P.3d 776(2017)(alteration in
original)(quoting 77/// v. Sacred Heart Med. Ctr., 143 Wn. App. 438, 447, 177
P.3d 1152(2008)). In Frausto, we explained that whether a nurse "has the
requisite specialized knowledge to qualify as an expert on causation" depends on
the nurse's "particular scope of practice and expertise." Id. at 243. Tencer admits
to having no scope of practice and expertise regarding the forces involved in
childbirth. He admitted this on direct examination:
Q: Have you ever done a labor and delivery case before this one?
A: No,I have not.
Verbatim Report ofProceedings(VRP)(Oct. 27, 2015) at 9. And again on cross-
examination. Id. at 26 ("I've never been involved in labor and delivery.").
Further, there is no indication that Tencer's general work regarding the human
spine directly translates to the specific circumstances involved in neonatal brachial
plexus injuries.
LM. V. Hamilton, No. 95173-0 (Gonzalez, J., concurring in result only)
The majority's reasoning that Tencer, as "a biomechanicai engineer, is able
to read the latest science, learn the forces at play, and apply that new knowledge to
what he already knows about the spine" is erroneous, dangerous, and
presumptuous. Majority at 27. Tencer's review of a single report discussing the
forces involved in childbirth does not qualify him to testify. Allowing him to
testify runs contrary to our focus on the expert's relevant experience. See, e.g.,
Katare, 175 Wn.2d at 38-39(holding an attorney with "17 years of experience in
the field of child abduction" cases was qualified to testify about risk factors for
child abductions). In other words, under the majority's reasoning, any attorney
who reads a paper on child abductions in preparation for trial would be qualified to
testify as a child abduction expert.
Further, Tencer puts forward an improperly speculative opinion based on
insufficient underlying data that "he looked at." See majority at 26("And to
prepare for this case, he looked at the latest science regarding the biomechanics of
childbirth."). This is simply not enough. "[Cjourts must scrutinize the expert's
underlying information ... to ensure that the opinion is not mere speculation,
conjecture, or misleading.'''' Johnston-Forbes, 181 Wn.2d at 358 (emphasis added)
(citing Stedman v. Cooper, 111 Wn. App. 9, 18, 292 P.3d 764(2012)). The report
Tencer relies on expressly concludes that "there are no data to quantify the
L.M. V. Hamilton, No. 95173-0 (Gonzalez, J., concurring in result only)
threshold pressures needed to induce traction versus compression related nerve
injury." Clerk's Papers at 3204. That report warns that
the assumptions in this study used to calculate the maternal expulsive
efforts were actually generated under normal conditions rather than
during an obstructive process . ...[which] suggests that these data
may have underestimated those maternally derived forces and that
during a shoulder dystocia event there may be an even greater
divergence of attributable forces between endogenous and exogenous
sources.
Id. Thus, Tencer's opinions regarding the comparative forces involved in
childbirth, as they relate to the primary contested issue in this case—
causation—cannot be supported by the very information on which his
opinion is purportedly based.'
The trial court barred Tencer from opining directly on the issue of
causation but ruled that he could testify generally to help the jury understand
the forces at play. But general "[sjcientific evidence that does not help the
trier of fact resolve any issue of fact. . . does not meet the requirements of
'The majority acknowledges this "analytical gap" in the underlying data but appears to confuse
the trial court's Frye determination about the general acceptance of the science undergirding the
natural forces of labor theory with the determination of whether Tencer's specific testimony was
based on sufficient underlying data. See majority at 28; Frye v. United States, 54 App. D.C. 46,
293 F. 1013 (1923). Even if the science generally allows for a medical causation opinion, it does
not support the conclusion that Tencer could adequately testify, particularly when his
nonmedical expert opinion was offered to induce an inference about medical causation. See
Stedman, 111 Wn. App. at 20 (trial court excluding Tencer's testimony in automobile accident—
and upheld on appeal—because his "clear message" was causation).
It should also be noted that the majority's affirmation of the trial court's Frye
determination in this case—finding that the natural forces of labor theory is currently generally
accepted in the scientific community—does not foreclose the possibility of a successful
challenge to the theory at a future Frye hearing, as the underlying science continues to develop.
LM. V. Hamilton, No. 95173-0 (Gonzalez, J., concurring in result only)
ER 702." State v. Greene, 139 Wn.2d 64, 73, 984 P.2d 1024(1999)(citing
Reese v. Stroh, 128 Wn.2d 300, 311, 907 P.2d 282(1995)(Johnson, J.,
concurring)). Here, the primary issue in dispute at trial was causation, which
Tencer was specifically prohibited from testifying about. The specific
"forces at play" in this case were not known, and Tencer never considered
those specific forces in forming his opinion testimony.^
Additionally, despite being expressly prohibited from testifying about
medical causation, it appears Tencer's testimony informed a medical
causation inference. See Stedman, 172 Wn. App. at 20. Nonetheless,
whatever effect Tencer's improper testimony may have had on the jury's
medical causation determination, it was likely insignificant when compared
to the medical causation evidence admitted through otherwise qualified
medical experts. See Brown v. Spokane County Fire Prot. Dist. No. 1, 100
Wn.2d 188, 196, 668 P.2d 571 (1983)("We find that the evidence, being
merely cumulative in nature, was harmless error."). Therefore, Tencer's
testimony was ultimately harmless and I concur in result.
^ At trial, Tencer confirmed that "nobody measured the force in Ms. Hamilton's hands if she used
any in facilitating [L.M.J's birth." VRP (Oct. 27, 2015) at 16. Additionally, in his discussion of
the average endogenous forces involved in labor, Tencer emphasized "that these numbers don't
apply specifically to this case." Id. at 15.
LM. V. Hamilton, No. 95173-0 (Gonzalez, J., concumng in result only)
7^