In the
United States Court of Appeals
For the Seventh Circuit
____________________
No. 15‐2602
SANDRA HALL, special administrator of
the estate of Chelsea Weekley,
Plaintiff‐Appellant,
v.
ANN FLANNERY, et al.,
Defendants‐Appellees.
____________________
Appeal from the United States District Court for the
Southern District of Illinois.
No. 13 CV 914 — Staci M. Yandle, Judge.
____________________
ARGUED FEBRUARY 17, 2016 — DECIDED NOVEMBER 4, 2016
____________________
Before BAUER, FLAUM, and WILLIAMS, Circuit Judges.
WILLIAMS, Circuit Judge. Chelsea Weekley suffered a skull
fracture as an infant and underwent surgery 17 years later to
fix it. She died several days after the surgery, and her mother,
Sandra Hall, sued the hospital and the surgeons. Hall argued
that the surgery caused Weekley to suffer a seizure and die,
and that the surgeons should have prescribed anti‐seizure
2 No. 15‐2602
medication. But the defendants argued that no seizure had oc‐
curred and that a heart‐related ailment was the likely cause of
death. A jury trial was held and the jury found in the defend‐
ants’ favor.
On appeal, Hall argues that the district judge erroneously
permitted three of the defendants’ experts to opine about
Weekley’s likely cause of death. We conclude that Hall for‐
feited her arguments as to two of these experts by making per‐
functory and underdeveloped arguments concerning the ex‐
perts’ testimony, qualifications, and methodology. However,
we find that the third expert lacked the requisite qualifica‐
tions to opine that Weekley’s heart ailment was the likely
cause of death. Because there is a significant chance that the
erroneous admission of this expert testimony affected the out‐
come of the trial, we vacate the district court’s judgment and
remand for further proceedings.
I. BACKGROUND
A. Weekley’s Surgery and Death
When Chelsea Weekley was approximately five months
old, she was dropped and suffered a skull fracture. As the
fracture expanded over time, a cyst formed in the area. The
fracture and cyst did not become a cause for concern until, at
the age of 17, she was hit in the head and suffered a loss of
consciousness, blurred vision, and dizziness. After CT and
MRI scans confirmed the extent of the fracture and the cyst,
Weekley underwent a “cranioplasty” surgery to repair the
fracture and the area of the dura (the thick membrane sur‐
rounding the brain) where the cyst had formed. The surgery
was performed at SSM Cardinal Glennon Children’s Hospital
No. 15‐2602 3
(“Hospital”) by Dr. Ann Flannery, a neurosurgeon, and Dr.
Raghuram Sampath, a neurosurgical resident.
Weekley was discharged a day after the surgery and was
found dead in her bed three days later. The coroner observed
that Weekley was in a “normal resting position,” that her legs
were straight and her ankles crossed, and that her right arm
was bent near her head “as if using it to lay on.” The coroner
also observed that her hands were “cramped up,” that her
bladder was empty, and that her feet were near the headboard
while her head was near the foot of the bed.
Weekley’s autopsy was performed by Dr. Raj Nanduri, a
board‐certified forensic pathologist. According to Dr. Nan‐
duri, forensic pathology concerns the effect of sudden, acci‐
dental, and suicidal death on the human body. After perform‐
ing a physical, microscopic, and toxicological examination of
Weekley’s body, Dr. Nanduri was unable to identify a cause
of death. So she asked Dr. Mary Case, a neuropathologist, to
examine Weekley’s brain. Dr. Case found that the surgery
damaged the dura and surface of Weekley’s brain. Based on
this finding, Dr. Nanduri concluded that Weekley had died
from a seizure brought about by the surgical damage. Neither
Dr. Nanduri nor Dr. Case was aware of or had reviewed the
pre‐surgery CT and MRI scans when they made their find‐
ings.
B. Pre‐Trial Proceedings
Weekley’s mother, Sandra Hall, sued Dr. Flannery, Dr.
Sampath, and the Hospital, alleging that they provided Week‐
ley with negligent post‐operative care, and that this negli‐
gence caused Weekley to suffer a seizure and die. Before trial,
Hall filed two motions in limine (“MILs”) that concerned three
4 No. 15‐2602
of the defendants’ expert witnesses: Dr. John Ruge, a pediatric
neurologist; Dr. Douglas Miller, a neuropathologist; and Dr.
Steven Rothman, a pediatric neurologist.
In MIL #48, Hall sought to bar Dr. Miller from testifying
that anything other than a seizure had caused Weekley’s
death, on the ground that Dr. Miller had not provided such
an opinion to a reasonable degree of medical certainty. The
district judge granted this MIL, though only to the extent that
Dr. Miller had in fact failed to disclose any such opinion.
In MIL #49, Hall sought to bar the defendants and their
witnesses from denying that Weekley’s death was caused by
a seizure. In doing so, Hall argued that Dr. Ruge and Dr. Roth‐
man were “not qualified through education or experience to
give an opinion to a reasonable degree of medical certainty as
to Weekley’s forensic cause of death.” In addition, Hall ar‐
gued that Dr. Ruge had failed to offer any scientific explana‐
tion for his opinion that Weekley had not died from a seizure,
and that Dr. Rothman had failed to offer any cause‐of‐death
opinions to a reasonable degree of medical certainty. The dis‐
trict judge denied the MIL, noting that the defendants’ experts
could provide any cause‐of‐death opinions that had been pre‐
viously disclosed.
C. Trial Proceedings
At trial, the defendants elicited cause‐of‐death testimony
from Dr. Ruge, Dr. Miller, and Dr. Rothman. Dr. Ruge testi‐
fied that Weekley’s death was not brought about by a seizure,
and opined that “focal interstitial chronic inflammation” of
Weekley’s heart (i.e., thickening of the heart’s connective tis‐
sue) was the likely cause of death. Hall’s attorney objected im‐
mediately, stating,
No. 15‐2602 5
[T]here’s been absolutely no foundation laid, no
qualifications, nothing that would suggest that
this gentleman is qualified to give, nor has that
been disclosed as one of the opinions as to cause
of death.
A sidebar ensued in which the parties and the district judge
focused on whether Dr. Ruge had previously expressed these
opinions with the requisite degree of medical certainty. No
one mentioned Dr. Ruge’s qualifications or methodology. Af‐
ter consulting Dr. Ruge’s expert report and deposition tran‐
script, the district judge concluded that the opinions had been
properly disclosed and did not violate her ruling on MIL #49.
Dr. Miller testified next. Before he shared his cause‐of‐
death opinions, Hall’s attorney objected, stating,
The Court has already determined after argu‐
ment and briefing that defendants’ expert Dr.
Douglas Miller is barred from testifying, sug‐
gesting or implying that Chelsea Weekley’s
cause of death was anything other than a sei‐
zure. In addition, this motion in limine was also
granted that defendants’ opinion witnesses can‐
not express any opinions as to cause of Chelsea
Weekley’s death that has [not] previously been
stated to a reasonable degree of medical cer‐
tainty.
The district judge concluded that although Dr. Miller had pre‐
viously stipulated that he had reached his opinions with a rea‐
sonable degree of medical probability but not medical certainty,
his opinions had been adequately shared before trial and thus
would not constitute a prejudicial surprise to Hall. Dr. Miller
6 No. 15‐2602
then testified that “it’s overwhelmingly probable that [Week‐
ley’s death] was not caused by a seizure.”
Finally, Dr. Rothman testified that he did not believe
Weekley suffered any seizures before her death. Hall did not
object to any of Dr. Rothman’s cause‐of‐death opinions dur‐
ing trial.
At the end of trial, the jury returned a general verdict
“find[ing] for all of the defendants and against the plaintiff.”
This appeal followed.
II. ANALYSIS
Hall argues on appeal that the district court erred in per‐
mitting Dr. Ruge, Dr. Miller, and Dr. Rothman to testify about
the specific cause of Weekley’s death. The admissibility of ex‐
pert testimony is governed by Federal Rule of Evidence 702
and Daubert v. Merrell Dow Pharmaceuticals., 509 U.S. 579
(1993). Such testimony is permitted if the witness is “an expert
by knowledge, skill, experience, training, or education,” and
her opinion is “the product of reliable principles and meth‐
ods” that have been reliably applied to the facts of the case.
FED. R. EVID. 702. Because we are not concerned with the wit‐
ness’s general qualifications but instead with his “foundation
for … answer[ing] a specific question[,] … we must look at
each of the conclusions he draws individually to see if he has
the adequate education, skill, and training to reach them.”
Gayton v. McCoy, 593 F.3d 610, 617 (7th Cir. 2010) (citations
and internal quotation marks omitted).
We review de novo whether a district judge has properly
followed Rule 702 and Daubert. Kunz v. DeFelice, 538 F.3d 667,
675 (7th Cir. 2008). So long as the judge applied the Rule
No. 15‐2602 7
702/Daubert framework, we review the judge’s decision to ad‐
mit or exclude expert testimony for abuse of discretion. Id. If,
however, the district judge failed to apply the framework, we
review the judge’s decision de novo. Metavante Corp. v. Emi‐
grant Sav. Bank, 619 F.3d 748, 760 (7th Cir. 2010); see also United
States v. Adame, 827 F.3d 637, 645 (7th Cir. 2016); Naeem v.
McKesson Drug Co., 444 F.3d 593, 608 (7th Cir. 2006).
Even if an expert’s testimony was erroneously admitted or
excluded, reversal is not warranted unless the error has af‐
fected a party’s “substantial rights.” FED. R. CIV. P. 61; see
Naeem, 444 F.3d at 608–09. This occurs when the erroneous
ruling has had a “substantial influence over the jury, and the
result reached was inconsistent with substantial justice.” Far‐
faras v. Citizens Bank & Trust of Chi., 433 F.3d 558, 564 (7th Cir.
2006) (citation omitted); Jones v. Lincoln Elec. Co., 188 F.3d 709,
725 (7th Cir. 1999). “Evidentiary errors satisfy this standard
only when a significant chance exists that they affected the
outcome of the trial.” EEOC v. Mgmt. Hospitality of Racine, Inc.,
666 F.3d 422, 440 (7th Cir. 2012) (quoting Old Republic Ins. Co.
v. Emp’rs Reinsurance Corp., 144 F.3d 1077, 1082 (7th Cir.
1998)); DeBiasio v. Ill. Cent. R.R., 52 F.3d 678, 685 (7th Cir.
1995).
A. Claim Forfeited as to Dr. Miller and Dr. Rothman
In her appellate brief, Hall states in conclusory fashion
that Dr. Miller and Dr. Rothman should not have been al‐
lowed to testify that seizure was not the cause of Weekley’s
death. But Hall makes no effort to explain why either doctor’s
cause‐of‐death testimony was improperly admitted, or to
identify the specific testimony that was improperly admitted.
8 No. 15‐2602
This failure is fatal, as “we are not in the business of formu‐
lating arguments for the parties.” United States v. McClellan,
165 F.3d 535, 550 (7th Cir. 1999).
Hall does cite Dr. Miller’s testimony that an epilepsy‐re‐
lated cause‐of‐death finding can be made in the absence of
other potential causes such as heart attack, as well as Dr. Roth‐
man’s testimony that clenched fists can be linked not only to
seizure but also to heart attack and lung disease. However,
Hall failed to take the critical next step of arguing that Dr. Mil‐
ler and Dr. Rothman lacked the requisite qualifications and/or
methodology to supply this testimony. Rather, Hall merely
cited this testimony to underscore her contention that Dr.
Ruge had supplied “wholly unfounded and baseless cause of
death testimony.” See Estate of Moreland v. Dieter, 395 F.3d 747,
756 (7th Cir. 2005) (“The defendants’ Daubert challenge to the
testimony of a different expert hardly suffices to preserve the
argument against [the expert at issue].”). Indeed, Hall con‐
ceded at oral argument that she was not arguing that Dr. Mil‐
ler’s and Dr. Rothman’s testimony violated Rule 702 and
Daubert. So Hall has forfeited her claim as to Dr. Miller and
Dr. Rothman. See Otto v. Variable Annuity Life Ins. Co., 134 F.3d
841, 854 (7th Cir. 1998) (“This court has refused to consider
unsupported or cursory arguments.”); United States v. Berko‐
witz, 927 F.2d 1376, 1384 (7th Cir. 1991) (holding that “per‐
functory and undeveloped arguments” are forfeited on ap‐
peal).
No. 15‐2602 9
B. Reversible Error Involving Dr. Ruge
1. Rule 702/Daubert Framework Should Have Been
Applied
Hall argues that the district judge erred in permitting Dr.
Ruge to testify that Weekley’s cause of death was not attribut‐
able to seizure, and that a heart‐related issue was the likelier
explanation. Both Hall and the defendants contend that we
should review the admission of this testimony for abuse of
discretion. But that overlooks the fact that the abuse of discre‐
tion standard is available only when the district judge actu‐
ally applied the Rule 702/Daubert framework, which did not
occur here.
In MIL #49, Hall argued that Dr. Ruge offered cause‐of‐
death opinions without being “qualified through education
or experience” and without the requisite “scientific explana‐
tion.” With that challenge to Dr. Ruge’s credentials, the dis‐
trict judge should have conducted a Daubert inquiry, even
though Hall did not expressly reference Daubert or Rule 702
by name. And when Hall objected at trial that “there’s been
absolutely no foundation laid, no qualifications, nothing that
would suggest that this gentleman is qualified to give … opin‐
ions as to cause of death,” the district judge was squarely
faced with a need to determine if Dr. Ruge was qualified as
an expert in this area, even if the word “Daubert” was not spo‐
ken.
But the objections did not prompt the judge to examine Dr.
Ruge’s qualifications and methodology or to apply the Daub‐
ert test. Instead, the judge focused solely on whether the chal‐
lenged opinions had been previously disclosed. Perhaps even
more curiously, neither party made any effort to clarify that
10 No. 15‐2602
Hall had in fact invoked Rule 702 and Daubert, and that the
district judge should therefore comment on more than
whether the opinions had been previously disclosed. The par‐
ties’ failure to do so, however, did not extinguish the need to
apply the Rule 702/Daubert framework to Dr. Ruge’s opinions.
Because that application never occurred, our review of the ad‐
mission of these opinions is de novo.
2. Adequate Qualifications and Methodology for
Dr. Ruge’s Seizure Opinion
At trial, Dr. Ruge opined that Weekley had not suffered a
seizure before she died. He noted that she had no docu‐
mented history of seizures, and that her body and bed did not
display the typical signs of seizure such as violent convul‐
sions, tongue damage, and urinary incontinence. He also
stated that seizures typically do not result from cranioplasty
(the surgical procedure Weekley underwent), and that the
cranioplasty here had not damaged Weekley’s brain.
This opinion was not erroneously admitted. For one, Dr.
Ruge possessed sufficient qualifications to opine on the oper‐
ation performed and the possible occurrence of a seizure af‐
terward. At the time of trial, Dr. Ruge had practiced pediatric
neurosurgery for approximately 25 years and was serving as
the chief of pediatric neurosurgery for the Advocate Health
Care system, which encompassed two major children’s hospi‐
tals and approximately ten other hospitals. In addition, he
was certified by the American Board of Neurological Surgery,
was affiliated with multiple neurological and medical socie‐
ties, and was a former editorial board member for the publi‐
cations Critical Reviews in Neurology and Child’s Nervous Sys‐
tem. And perhaps most notably, he had operated on growing
skulls fractures like Weekley’s, and had published articles on
No. 15‐2602 11
various pediatric neurosurgery topics including epilepsy, cra‐
nial cysts, and severe head injury.
In addition, Dr. Ruge’s seizure‐related opinions were
based on sufficiently reliable methodology. Dr. Ruge arrived
at his conclusions based on his review of the autopsy report;
Weekley’s medical records, including the MRI and CT scans
taken before surgery, Dr. Flannery’s operative report, and Dr.
Flannery and Dr. Sampath’s post‐surgery progress notes; and
deposition testimony. See Gayton, 593 F.3d at 618 (holding that
district court abused its discretion in finding expert’s meth‐
odology unreliable where expert made differential diagnosis
based on decedent’s autopsy report and medical records and
testimony of prison guards and other witnesses); Walker v. Soo
Line R.R. Co., 208 F.3d 581, 591 (7th Cir. 2000) (holding that
district judge did not abuse his discretion in admitting expert
testimony informed by expert’s experience and examination
of medical records, despite lack of in‐person examination). In
addition, Dr. Ruge relied on his medical experience, which as
discussed above is substantial, particularly with regard to pe‐
diatric neurosurgery. See Kumho Tire Co. v. Carmichael, 526 U.S.
137, 156 (1999) (“[N]o one denies that an expert might draw a
conclusion from a set of observations based on extensive and
specialized experience.”); Metavante Corp., 619 F.3d at 761
(“An expert’s testimony is not unreliable simply because it is
founded on his experience rather than on data … .”); Smith v.
Ford Motor Co., 215 F.3d 713, 718 (7th Cir. 2000) (“While exten‐
sive academic and practical expertise in an area is certainly
sufficient to qualify a potential witness as an expert, Rule 702
specifically contemplates the admission of testimony by ex‐
perts whose knowledge is based on experience.” (citations
and internal quotation marks omitted)).
12 No. 15‐2602
Hall contends that Dr. Ruge lacked the requisite qualifica‐
tions because pathology is not his area of professional focus.
However, this argument ignores the fact that “[o]rdinarily,
courts impose no requirement that an expert be a specialist in
a given field.” Gayton, 593 F.3d at 618 (citation omitted); see
also Gaydar v. Sociedad Instituto Gineco‐Quirurgico y Planifica‐
cion Familiar, 345 F.3d 15, 24–25 (1st Cir. 2003) (“The proffered
expert physician need not be a specialist in a particular medi‐
cal discipline to render expert testimony relating to that disci‐
pline. In fact, it would have been an abuse of discretion for the
court to exclude [the expert]’s testimony [about plaintiff’s
pregnancy] on the sole basis that his medical specialty was
something other than gynecology or obstetrics.”); Pineda v.
Ford Motor Co., 520 F.3d 237, 244 (3d Cir. 2008) (explaining that
a district court abuses its discretion by excluding testimony
simply because “the proposed expert does not have the spe‐
cialization that the court considers most appropriate” (cita‐
tion omitted)). The fact that an expert may not be a specialist
in the field that concerns her opinion typically goes to the
weight to be placed on that opinion, not its admissibility. See,
e.g., Huss v. Gayden, 571 F.3d 442, 452 (5th Cir. 2009); Mitchell
v. United States, 141 F.3d 8, 15 (1st Cir. 1998); Kannankeril v.
Terminix Int’l, Inc., 128 F.3d 802, 809 (3d Cir. 1997).
Here, the issue of whether a seizure occurred shortly be‐
fore Weekley’s death did not concern knowledge that is held
solely by pathologists. Dr. Nanduri, the pathologist who ex‐
amined Weekley after her death, testified that a seizure‐re‐
lated cause‐of‐death finding is made by excluding all other
apparent causes, and that she arrived at her finding here
based on the damage to Weekley’s dura and cortex—damage
that a non‐pathologist could have observed. Moreover, Dr.
Ruge stated that he “routinely cared for patients who … have
No. 15‐2602 13
seizures as part of their neurosurgical condition,” witnessed
numerous seizures himself, and operated on individuals with
head injuries comparable to Weekley’s. So Dr. Ruge pos‐
sessed the requisite qualifications to testify about seizures. See
Gayton, 593 F.3d at 618 (holding that general practitioner
could testify about possible effects of certain medications on
decedent’s heart condition because the issue did not concern
“specialized knowledge held only by cardiologists”); Banister
v. Burton, 636 F.3d 828, 831–32 (7th Cir. 2011) (holding that
emergency‐room surgeon who treated shooting victim was
adequately qualified to testify about victim’s ability to throw
or crawl at the time of treatment, despite not being a biome‐
chanics expert or an orthopedic surgeon).
3. Inadequate Qualifications for Dr. Ruge’s Heart
Opinion
While Dr. Ruge was qualified to opine on Weekley’s sur‐
gery and the possibility of seizure, this qualification does not
extend to his opinion that Weekley’s heart‐related issue was
the likelier cause of death. See Gayton, 593 F.3d at 617 (“[W]e
must look at each of the conclusions [an expert] draws indi‐
vidually to see if he has the adequate education, skill, and
training to reach them.” (citations and internal quotation
marks omitted)).
Neither Dr. Ruge’s trial testimony nor his expert report
and curriculum vitae indicate that he possesses any special‐
ized education, knowledge, experience, or skill concerning fo‐
cal interstitial chronic inflammation specifically, or more
broadly cardiology. Indeed, Dr. Ruge acknowledged at trial
that when he read the inflammation finding in Weekley’s au‐
topsy report, he “didn’t know what that was exactly.” So he
14 No. 15‐2602
conducted a Google search and found several papers explain‐
ing that it is “a finding in young athletes who die suddenly of
cardiac arrhythmias,” even though their “hearts can look very
normal.” Based on this research, he opined that focal intersti‐
tial chronic inflammation “makes more sense [as a cause of
death] based on the whole story, the whole picture.”
We do not doubt that Dr. Ruge is an intelligent doctor who
possesses considerable knowledge about surgery, pediatrics,
and neurology. However, the record lacks sufficient evidence
demonstrating that this knowledge and the related experi‐
ences render Dr. Ruge qualified to opine about Weekley’s
heart. See Dura Auto. Sys. of Ind., Inc. v. CTS Corp., 285 F.3d 609,
613 (7th Cir. 2002) (remarking that a surgeon “would be com‐
petent to testify that the cancer was too advanced for surgery,
but [that] in offering the additional and critical judgment that
the radiologist should have discovered the cancer sooner he
would be, at best, just parroting the opinion of an expert in
radiology”); Jones v. Lincoln Elec. Co., 188 F.3d 709, 723–24 (7th
Cir. 1999) (holding that district court should have barred ma‐
terial scientist from testifying about conclusions that “were
rooted in medical knowledge and training which [he] did not
have” and that were “derived primarily, if not completely”
from a physiologist); see also Avila v. Willits Envtl. Remediation
Trust, 633 F.3d 828, 839 (9th Cir. 2011) (concluding that chem‐
ist, who had expertise in cancer immunology and medical tox‐
icology, had no “special training or knowledge regarding
metal working industries” and could not opine that power
plant’s activities created dioxins); Wheeling Pittsburgh Steel
Corp. v. Beelman River Terminals, Inc., 254 F.3d 706, 715–16 (8th
Cir. 2001) (concluding that hydrologist was qualified to testify
about flood‐risk management but not about safe warehousing
practices). Because Dr. Ruge did not possess the requisite
No. 15‐2602 15
qualifications to opine about the impact of Weekley’s heart on
her cause of death, we need not address his methodology.
4. Hall’s Substantial Rights Were Affected
The fact that Dr. Ruge’s heart‐related cause‐of‐death testi‐
mony was erroneously admitted does not automatically enti‐
tle Hall to a new trial. Rather, she must show that this error
had a “substantial influence over the jury.” Farfaras, 433 F.3d
at 564. We conclude that it did.
It is undisputed that Weekley’s cause of death was a criti‐
cal issue at trial. Hall pointed to seizure—a relatively difficult
fact to prove since (as both parties agree) such a finding is
made only by ruling out all other possible alternatives. It is no
surprise that the defendants chose not only to argue that a sei‐
zure had not occurred, but also to offer an alternative cause—
heart troubles. And Dr. Ruge played a critical role supporting
this alternative cause, testifying about multiple studies he had
read that linked the heart condition that Weekley had to the
circumstances under which she passed away.
Critically, the import of Dr. Ruge’s testimony cannot be
minimized on the ground that it was merely “cumulative” of
testimony provided by other experts. See Naeem, 444 F.3d at
609 (finding improperly admitted expert testimony did not
affect substantial rights because certain of the expert’s objec‐
tionable statements were “corroborated by other witnesses”);
Palmquist v. Selvik, 111 F.3d 1332, 1339, 1342 (7th Cir. 1997)
(finding that exclusion of evidence was harmless error be‐
cause the proposed evidence was cumulative). To be sure, Dr.
Miller and Dr. Rothman briefly referenced the effect a heart
attack can have on cause‐of‐death findings generally, while
16 No. 15‐2602
Dr. Nanduri and Dr. Case acknowledged that heart disturb‐
ances can result in death for a healthy young adult. However,
Dr. Ruge was the only expert to opine about the purportedly
“numerous papers” that identify young athletes who died
suddenly of heart‐related illness. We cannot ignore the dis‐
tinct possibility that Dr. Ruge’s discussion of these publica‐
tions played a key role in the jury’s verdict, given the thresh‐
old nature of the cause of death inquiry. See Chapman v. May‐
tag Corp., 297 F.3d 682, 688 (7th Cir. 2002) (remanding for new
trial where precise impact of expert’s erroneously admitted
testimony on comparative fault could not be determined,
given the jury’s general verdict); see also Estate of Barabin v.
AstenJohnson, Inc., 740 F.3d 457, 465–67 (9th Cir. 2014) (en
banc) (remanding for new trial where district court errone‐
ously permitted expert to testify about evidence that was
“critical” to plaintiffs’ case); Wheeling Pittsburgh Steel, 254 F.3d
at 715 (finding reversible error where district court permitted
hydrologist to repeatedly testify beyond scope of his expertise
“on ultimate issues of fact that the jury was required to an‐
swer”).
The defendants contend that reversal would be improper
because “there is no basis to conclude that admission of the
Defendants’ experts’ testimony influenced the jury’s verdict.”
They argue that even if the jury had not heard any testimony
from the defendants’ experts regarding alternative causes of
death, the jury could have found for the defendants on the
grounds that they did not breach their standard of care, or
that any such breach did not cause Weekley’s death. In sup‐
port, the defendants cite several Illinois state court decisions
that found a new trial to be unnecessary where it was possible
that the jury’s verdict rested on an issue that was not subject
to appeal. See Tabe v. Ausman, 902 N.E.2d 1153, 1159 (Ill. App.
No. 15‐2602 17
Ct. 2009); Strino v. Premier Healthcare Assocs., P.C., 850 N.E.2d
221, 229–30 (Ill. App. Ct. 2006); Krklus v. Stanley, 833 N.E.2d
952, 959–60 (Ill. App. Ct. 2005).
But state law is not applicable to this inquiry. “In this cir‐
cuit the harmlessness standard is treated as procedural and
therefore in a diversity case is governed by federal law and
[Rule] 61.” Sokol Crystal Prods., Inc. v. DSC Commc’ns Corp., 15
F.3d 1427, 1435 (7th Cir. 1994) (citation and footnote omitted);
see also 11 CHARLES A. WRIGHT ET AL., FEDERAL PRACTICE &
PROCEDURE § 2883 (3d ed. 2016) (“It is unsound [for a federal
court to apply a state court’s harmless‐error standard] be‐
cause the harmless‐error doctrine, explicitly stated both in
Rule 61 and in an Act of Congress, is an important principle
of judicial administration that goes to the proper relation be‐
tween the trial judge and the jury and the proper relation be‐
tween appellate courts and trial courts.”). Because the defend‐
ants have not satisfied Rule 61’s harmless‐error standard, a
new trial is warranted.
III. CONCLUSION
We REVERSE the district judge’s decision to admit Dr.
Ruge’s heart‐related cause‐of‐death testimony, VACATE the
judgment, and REMAND the case for proceedings consistent
with this opinion.