Ponte v. Bustamante ex rel. Bustamante

DAVID J. SCHENCK, JUSTICE,

dissenting

The Court concludes in a thoughtful and comprehensive opinion that appellees offered no evidence of causation. I regret that I find myself unable to join it. Because I would hold that the record, viewed as a whole and in the light most favorable to the verdict, reflects at least some evidence of cause in fact, I respectfully dissent.

The Court clearly explains the applicable law. To establish cause in fact, the plaintiff must introduce evidence of a “reasonable medical probability” or a “reasonable probability” that her injury was caused by the defendant’s negligence. As the Court explains, this standard *88“‘mean[s] simply that it is “more likely than not” that the ultimate harm or condition’ resulted from the defendant’s negligence.” Ponte v. Bustamante, No. 05-12-01394-CV, Opinion on Rehearing at 5 (“Opinion”) (quoting Jelinek v. Casas, 328 S.W.3d 526, 532-33 (Tex.2010)). Where I differ from the Court’s analysis is in the application of this standard. I would not require (1) the plaintiff to prove that each defendant’s negligence, standing alone, caused the injury; (2) the plaintiff to disprove all other possible causes of her injury, no matter how unlikely; or (3) proof to a medical certainty that absent defendants’ negligence, Daniella would have a sighted life.

As all involved in the case appear to agree, baby Daniella was highly likely to develop ROP, a condition that without timely diagnosis and competent surgical intervention could cause her permanent vision loss.1 With supporting record evidence that the defendants had failed to timely diagnose or initiate the necessary treatment, and that the surgery, when belatedly performed, was significantly mishandled, the jury found all defendants negligent. . We leave the jury’s implied findings of negligence in each of these respects undisturbed. Given the known risks to the patient, there is little room for debating the foreseeability prong of proximate cause here. With negligence and foreseeability established, only the question of but-for causation remains.2

The question of causation in fact — or “but-for” cause — is usually among the more simple and obvious problems associated with legal liability in tort. By itself, but-for causation is far-reaching. The most vivid illustration of the breadth of the concept may come from the nursery rhyme relating the loss of a kingdom for want of a nail.3 It is precisely because of these far-reaching implications that literal but-for causation is not alone enough to establish legal liability. It is constrained by the additional requirement that the harm at issue be reasonably foreseeable as a consequence of the alleged misconduct.4 Thus, *89liability in this and other cases in which negligence has been established turns on combining but-for causation and foreseeability in the requirement of proximate cause.

Fairly summarized, Dr. Good’s extensive testimony, as supplemented by like testimony from Dr. Phelps, identified the negligence of each defendant and explained how it contributed to Daniella’s blindness. The acts of negligence identified by the Court, and established by the evidence, were (1) failure to examine Daniella at all during a critical time period; (2) failure to perform laser treatment promptly after determining its necessity; and (3) negligent performance of the laser treatment itself. But the Court concludes that the expert testimony about these acts “does not suffice to show but-for causation” because it “lacked factual explanation and support” or was “conclusory.” Opinion at 13, 24. In the Court’s view, the plaintiffs failed to explain “how and why” these acts, undis-putedly in violation of the standard of care, caused Daniella’s blindness. See, e.g., Opinion at 15 (“The question is whether Good explained how and why Llamas’s three acts of negligence caused the injury.”). The experts, in my view, answered these questions by providing specific evidence from Daniella’s medical records, their own subsequent examination of her, and from their own expertise about the progression and treatment of ROP in general and in Daniella’s case in particular. They could not, of course, pinpoint exactly when Daniella developed ROP, testify to a date on which her ROP became treatable, or quantify exactly the actual delays. Because Daniella was not examined for four weeks, there is no medical record to consult to determine the status and progression of her ROP during this critical time period. But there was evidence from which the jury could have found that timely diagnosis and properly performed treatment would have, more likely than not, resulted in a sighted life for Daniella.

Dr. Good offered his opinions, quoted by the Court, that both the examination schedule and the laser treatment itself fell below the applicable standards of care, and that these failures were a proximate cause of Daniella’s blindness. No witness disputed that prompt diagnosis and treatment of ROP was the accepted standard of care (as Dr. Ponte agreed, ROP should be “diagnosed as soon as it is diagnosable” and “treated as soon as it is treatable”),5 or that Dr.- Good had the requisite expertise in both treating patients and conducting research to draw reliable conclusions about the effect of these lapses from his review of Daniella’s treatment. His opinions were that earlier examination and appropriate laser treatment would have prevented *90Daniella’s blindness. I do not believe that opinion to be ipse dixit, because Dr. Good explained the consequences of delay to the jury and because even the published standards on which defendants relied warned that delay alone can result in blindness.

In addition to Dr. Good’s testimony, plaintiffs’ expert Dr. Phelps testified that if Drs. Ponte and Llamas had timely examined Daniella in accordance with the standard of care, they “would have seen the ROP as it started up or as it became established and before it became advanced.” If they had followed the standard of care, “more likely than not Daniel-la would have functional vision.” Thus, the only evidence offered at trial by any party was that timely and competent examination and treatment are the standard of care, and blindness is the foreseeable result when the standard is not met. Dan-iella’s experts then opined that Daniella is blind because she did not receive this timely and competent care.

Dr. Good also testified to his expert opinion that timely and competent “ROP laser therapy is effective in stopping the progression of ROP in most babies,” with a 75% success rate “or higher,” for “all comers.” Dr. Good was responding to a question regarding a chapter in a treatise written by one of the defense experts, Dr. Graham Quinn. Also, as appellees urge on rehearing, the ETROP6 study, showing timely laser therapy to have an overall success rate over 75%, “is legally sufficient evidence that performing the surgery properly would have resulted in a different outcome.”

I would conclude on this record that there is nothing missing from this causal chain. The defendants knew Daniella’s risk of ROP was almost certain. They also knew that ROP could result in blindness, and that standards had been accepted by the medical community to prevent that result. Even at the time, defendants understood that timely examination, and treatment if necessary, prevented blindness. Yet Daniella’s ROP was neither “diagnosed as soon as it was diagnosable” nor “treated as soon as it was treatable.” In my view, the “how and why” is that defendants allowed Daniella’s ROP to progress past the point where diagnosis and treatment, in her experts’ opinion, should have been made and undertaken. When treatment was belatedly undertaken, it was improperly performed. Viewing the evidence in the light most favorable to the jury’s verdict, and indulging every reasonable inference that would support it, see City of Keller v. Wilson, 168 S.W.3d 802, 820-22 (Tex.2005), Daniella would not be blind but for the (1) delay in diagnosis and treatment; (2) improperly performed treatment; or (3) both. In my view, the evidence supports any one of those three possible findings.

To be sure, had the laser therapy been performed without negligence, our causation inquiry would be simplified. Daniel-la’s blindness could have been a product of only one of two causes: (1) delaying the diagnosis and laser treatment, for which there is ample evidence, or (2) she had no hope of recovery regardless of her treatment — a notion supported by no evidence and contrary to the opinion of two experts and the probabilities suggested by the objective data. The fact that the causation problem is further obscured by additional negligence in performing the surgery does not add to the victim’s burden and would *91not support rendition of a take-nothing judgment in the face of a verdict apportioning fault as this one did.

As the jury was instructed, there may be one or more causes of an event. If there were some evidence that delay in treatment alone7 could not cause the harm complained of or contribute to the challenge in performing the laser treatment we would have something to weigh on the City of Keller scales. But the evidence here is entirely to the contrary: that regular, consistent examination of a child likely to develop ROP was essential to allow surgical

correction.8 Under the earlier, more lenient standards on which the defendants claimed to rely, Daniella should have been re-examined within two, or at most, three weeks of the initial examination. When Dr. Llamas next saw her a month later, her right eye already had “zone 1” disease and was hemorrhaging, and both it and her left eye required immediate laser treatment. While the guidelines called for the NICU to publish the examination schedule, to trigger automatic visits to avoid missing a deadline and to allow sufficient time for treatment “including transfer to another facility for treatment,” the NICU had done none of this and could not locate a laser (or arrange a transfer), delaying the procedure until the early evening of August 4. On these facts, the jury might have attributed the cause of Daniel-la’s blindness to the delay in the examination (including and especially as to her right eye), or to the further delay in performing the procedure (as to either eye), or to the negligence in the procedure itself.

In sum, Dr. Good explained how both Dr. Ponte and Dr. Llamas deviated from the applicable standards of care for babies at known risk for ROP, and further testified as to how these deviations were the proximate cause of Daniella’s blindness. This is, therefore, not a case where a credentialed expert appeared at trial simply to declare the harm to be a product of misfeasance, leaving the basis for the conclusion a mystery or in conflict with his own testimony concerning other possible causes.

On rehearing, appellees cite Merrill Dow Pharmaceuticals, Inc. v. Havner, 953 S.W.2d 706 (Tex.1997), to support their contention that epidemiological data may *92constitute legally sufficient evidence of causation. The Court instead relies on Havner to support its conclusion that the ETROP study is, not probative regarding causation. Opinion at 20-24. In my view, Havner’s analysis of causation in strict liability cases embraces a standard that, if anything, is too liberal for professional negligence cases, and in any event has little to offer in this setting. See Bostic v. Georgia-Pacific Co., 439 S.W.3d 332, 347-48 (Tex.2014) (“[w]e have never held that [Havner] applies universally to all tort cases where causation is an issue”). Hav-ner addresses the use of epidemiological studies to establish causation where direct evidence of causation is lacking and permits recovery to all plaintiffs where the overall risk of a harm to the general population exposed to a defective product is doubled. See Bostic, 439 S.W.3d at 349-50 (“where direct evidence of causation is lacking, scientifically reliable evidence in the form of epidemiological studies showing that the defendant’s product more than doubled the plaintiffs risk of injury appropriately corresponds to the legal standard of proof by a preponderance of the evidence”). In Havner, there was no direct evidence that the drug Benedictin caused the plaintiffs birth defects. Havner, 953 S.W.2d at 708-09. In addition to this issue of specific causation,. Havner addressed the use of epidemiological studies to establish general causation, that is, whether Be-nedictin could cause birth defects in anyone. See Bostic, 439 S.W.3d at 347- 48. In this case, Dr. Good did not rely on an epidemiological study to establish the probability that delayed or inadequate treatment of ROP would cause blindness in the general population, and opine that Daniella might be one of those cases. Instead, he testified that both Dr. Ponte and Dr. Llamas deviated from the applicable standards of care for babies at known risk for ROP, and these deviations were the proximate cause of Daniella’s blindness. The fact that objective data supported that conclusion does not detract from its weight. This was not a case where an expert was simply attempting to surmise actual causation by extrapolating from a statistical possibility of general causation in a broader population.

Neither Dr. Good’s failure to establish that Daniella’s blindness was attributed solely to one of the multiple acts of negligence here, nor his failure to explain why Daniella would not have been among the minority of patients (22%)9 who ultimately suffer blindness despite proper treatment renders his opinion empty ipse dixit. I would reject these additional burdens the Court imposes on a plaintiff to submit a negligence question to the jury.

Although it is no longer explicit in the Court’s opinion that each defendant’s negligence alone must be, more likely than not, a but-for cause of Daniella’s injuries, the Court maintains its criticism of Dr. Good’s testimony that “he predicated his opinion on the combined negligence of both Ponte and Llamas” in a sequence of events. Opinion at 12. But a defendant’s act or omission need not be the sole cause of an injury, as long as it is a substantial factor in bringing the injury about. Havner v. E-Z Mart Stores, Inc., 825 S.W.2d 456, 459 (Tex.1992).10 And there may be *93more than one proximate cause of an injury, as the jury was instructed here. See, e.g., Del Lago Partners, Inc. v. Smith, 307 S.W.3d 762, 774 (Tex.2010). As noted, Dr. Good and Dr. Phelps both testified as to how Dr. Ponte’s negligence in relation to the delayed diagnosis contributed to Dan-iella’s blindness. The evidence is that both doctors and the NICU, which Dr. Ponte led, collectively failed to establish a protocol adequate to timely diagnose critical-stage ROP and failed to timely diagnose it in Daniella, their patient. Likewise, the jury heard evidence that the procedure was delayed a further three days because the laser device could not be found. I would conclude that these acts of negligence, considered together, were shown to be a substantial factor in bringing about Daniella’s injury. See E-Z Mart Stores, Inc., 825 S.W.2d at 459; Del Lago Partners, Inc., 307 S.W.3d at 774.11

The Court also imposes a burden on plaintiffs to affirmatively disprove all other potential causes of an injury, regardless of likelihood of occurrence, in order to establish that a defendant’s negligence was more likely than not a cause in fact of an injury. See Opinion at 16-17 (Good “did not explain why he concluded Daniella would not have been among the 22% of babies who suffered blindness even after receiving proper laser treatment”).

Having established the treating physician’s negligence and the harm foresee-ably relating to it, and having proffered competent expert opinion — augmented by objective data supporting it — that the negligence was the probable cause of the foreseeable harm, a patient does not bear the further burden of negating all other possible causes of an injury in order to raise a fact issue with respect to causation. E-Z Mart Stores, Inc., 825 S.W.2d at 460-61. Under the Court’s standard, in any medical negligence case, a plaintiff could not raise a fact question as to whether a reasonable degree of probability supports causation without first affirmatively disproving — no matter how unlikely — all other potential complications of the surgery or preexisting conditions of the plaintiff. The concern here is that this same standard applies universally across virtually *94every setting, including general negligence, intentional torts and arguably, criminal offenses in which injury is an element.12 See, e.g., Paroline v. United States, — U.S. -, 134 S.Ct. 1710, 1719, 188 L.Ed.2d 714 (2014) (concept of proximate cause, including cause in fact and foreseeability, is applicable in both criminal and tort law). Suppose a father is timely diagnosed with a form of lymphoma having a 90% survival rate if diagnosed early and treated properly. Suppose further that a malicious heir wishing to advance his inheritance switches his parent’s prescribed lymphoma medication for a placebo. In a resulting civil wrongful death case, would appellants have us dismiss as ipse dixit a medical expert’s opinion that the switch more than likely caused the death, or direct a judgment of take nothing, absent proof from the expert establishing (1) why 10% of patients do not respond to the treatment and (2) why the decedent would not have been in the 10%? In a resulting criminal homicide case, would appellants advocate acquittal without similar proof? I would think that the expert’s opinion, bolstered by the objective data, is some evidence of but-for causation and allow the defendant to meet that evidence to persuade a jury to the contrary.

While it was possible that Daniella would have been blind even with proper treatment, on this record, viewed- as a whole, it is not probable. Rather, the opposite has been shown — not to a certainty perhaps, but certainly to a reasonable degree of medical probability. The Supreme Court has set the probability bar at 50% in Kramer. Kramer v. Lewisville Mem’l Hosp., 858 S.W.2d 397, 400 (Tex.1993). I would conclude that the plaintiffs have offered some evidence of causation by establishing the probability of a sighted life at 75% or higher, especially in the absence of record evidence suggesting any reason why Daniella’s prospects were reduced.

The Court relies on Jelinek to impose these burdens in addition to proof of a reasonable medical probability that Daniel-la’s injury was caused by appellants’ negligence. I would conclude that this ease is materially distinct from Jelinek. In Jeli-nek, a doctor testified that the plaintiffs pain was caused by the defendants’ failure to treat her infection with a particular antibiotic. 328 S.W.3d at 535-37. But the doctor also admitted on cross-examination that the symptoms he cited were equally consistent with two other infections, later found in the plaintiff, for which the absent antibiotic would not have been effective. Id. at 535-36. According to the expert himself, the plaintiffs symptoms were just as likely to have been caused by something other than the defendants’ negligence as by the negligence itself. On those facts it was impossible for the proof of negligence causation, including the expert’s own opinion, to preponderate.

Absent equally likely causes, I do not think the Jelinek court would require an *95expert who has explained why and how an injury was caused by one or more acts of negligence to also explain why some unknown and unmentioned variable other than negligence was not the cause of an injury in order for his opinion to constitute “some evidence.” There is no evidence to suggest that Daniella was destined to be blind or that she exhibited some objective characteristic that predicted that result. In effect, a plaintiff would be required to prove a medical certainty — that without negligence, treatment would always be successful-by proof that she did not suffer from any variable that might result in failure.

In my view, such a notion is contrary to settled Texas law. Quoting Havner, the court in Transcontinental Ins. Co. v. Crump, 330 S.W.3d 211, 217-18 (Tex.2010), explained that “a medical causation expert need not disprove or discredit every possible cause other than the one espoused by him” unless “evidence presents other plausible causes of the injury or condition that could be negated.” Id. (quoting Havner, 953 S.W.2d at 720) (internal quotation marks omitted). The court in Bostic, also citing Havner, described the application of this concept in asbestos-disease cases, explaining that “it properly stands for the proposition that, even in mesothelioma cases, liability cannot be imposed on every conceivable defendant whose product exposed the plaintiff to some unquantified amount of asbestos, without proof of something more.” Bostic, 439 S.W.3d at 341. These cases, in my opinion, do not require a plaintiff who has offered proof that the defendant’s negligence more than likely caused her injury to also speculate about other possible unknown causes and then disprove them. As this Court has explained, “[t]he plaintiff need not exclude all possibilities; it is sufficient to prove that the greater probability is that the defendant’s conduct, alone or in contribution with others, was the cause of the- harm.” First Assembly of God, Inc. v. Tex. Utils. Elec. Co., 52 S.W.3d 482, 493 (Tex.App.Dallas 2001, no pet.).

In Kramer, the court explained, “the ultimate standard of proof on the causation issue” in a medical malpractice case is “whether, by a preponderance of the evidence, the negligent act or omission is shown- to be a substantial factor in bringing about the harm and without which the harm would not have occurred.” 858 S.W.2d at 400. The court continued, “[t]he effect of these standards is to bar recovery where the defendant’s negligence deprived the tort victim of only a 50% chance or less of avoiding the ultimate harm.” Id. Proving that Daniella was not in the 22% (or fewer)13 who ultimately suffer blindness despite proper treatment would require proof that she was in the 78% for all of whom the treatment was effective, that is, proof of a 100% certainty that treatment would be successful. And there was nothing in the record to suggest how proof of 100% certainty could be made.14 Dr. Good’s testimony established that there was no distinction between the 22% of *96babies who suffered blindness and the 78% for whom laser treatment was effective; his opinion that laser therapy is effective in at least 75% of cases applied to “all comers,” not just to babies who did not suffer from other complicating conditions. In contrast to Kramer ’s standards, plaintiffs’ recovery here is barred unless they prove, by ruling out all potentially adverse factors, that defendants’ negligence deprived Daniella of medically-certain success, that is, 100% chance “of avoiding the ultimate harm.” See id. I do not construe Kramer to be so exacting.

Here, Dr. Good did not testify regarding equally likely causes of Daniella’s blindness. Instead, Dr. Good testified unequivocally that the delay in Daniella’s screening evaluation, the delay in laser treatment, and the inadequate laser treatment “each contributed to the poor visual outcome that Daniella experienced.” Dr. Good testified that “more likely than not,” Daniella’s blindness was caused by the negligence he and Dr. Phelps described, and cited the ETROP study showing a high success rate for properly treated patients to augment that conclusion. Under Jelinek, this testimony is sufficient to establish cause in fact. See Jelinek, 328 S.W.3d at 532-33. The notion that'some ROP patients exposed to negligence might, based on their particular circumstances, have been more likely to fall into the 22% of patients destined to be blind anyway is one that the defendants in such a case would want to develop in hopes of avoiding an adverse or directed verdict.15 But where, as here, the record, viewed as a whole, reveals only negligence and a 78% probability of a sighted life for all patients treated without negligence, I cannot conclude that there is no evidence of causation in fact for Daniella’s blindness.

CONCLUSION

I would grant appellees’ motion for rehearing and affirm the trial court’s judgment.

. Dr. Ponte, the medical director of the neonatal intensive care unit (“NICU”) that treated Daniella, testified that babies as premature as she was were 100% certain to develop ROP. He, together with Dr. Llamas, was responsible for establishing the examination schedule. Despite testimony reflecting the rapid progress of ROP and the need for surgical intervention within 48 or, perhaps, 72 hours of a determination of "threshold” ROP, Daniella went one month from her first examination to her second, at which point Dr. Llamas determined she required immediate laser surgery. Contrary to the published standards on which defendants rely, the NICU had no protocols requiring more prompt examination, despite the high risk of patients like Daniella developing ROP, and had no ready access to the laser needed to treat it.

. Indeed, given the nature of the risk and the presence of negligence one might argue that a reasonable lay juror might directly infer the requisite factual causation — a notion we need not explore in this case given the admission of Dr.' Good’s expert causation testimony. While expert opinion evidence is necessary to establish the standard of care and breach in medical malpractice cases, it is not invariably necessary to establish factual causation, depending on the nature of the claimed injury. Jelinek, 328 S.W.2d at 533 (noting expert testimony is the norm). Of course, where quali.fied expert opinion is admitted as to both negligence and causation on the grounds that it is helpful to the fact finder and reliable, it is probative of the causation question as well, unless it amounts to a mere ipse dixit declaration. Id.

. See, e.g., Providence Health Ctr. v. Dowell, 262 S.W.3d 324, 329 (Tex.2008) ("want-of-a-nail” approach to causation "squarely rejected” in IHS Cedars Treatment Ctr. of DeSoto, Tex., Inc. v. Mason, 143 S.W.3d 794, 798-800 (Tex.2004)).

. See generally Union Pump Co. v. Albritton, 898 S.W.2d 773, 777-78 (Tex.1995) (Cornyn, *89J., concurring, quoting Palsgraf v. Long Island R.R. Co., 248 N.Y. 339, 162 N.E. 99 (1928)), abrogated on other grounds by Ford Motor Co. v. Ledesma, 242 S.W.3d 32, 45-46 (Tex.2007).

. Delay in diagnosis and treatment, such as the jury impliedly found here as to all defendants, can be a contributing cause leading to blindness in an ROP patient, as Drs. Good and Phelps opined below, and as Dr. Llamas has previously argued to this Court. Llamas-Soforo v. Jimenez, No. 05-09-00102-CV, 2009 WL 3366560, at *3 (Tex.App.-Dallas Oct. 21, 2009, pet. denied) (mem.op.) (dismissing Llamas’s challenge to pre-trial expert opinion attributing blindness in baby born at 23 weeks to Llamas’s failure to apply laser treatment to affected portion of the eyes where Llamas urged such opinion was "conclusory” and suggested outcome was attributable to other physicians’ delay in diagnosing and sending patient for surgery); see also Gross v. Burt, 149 S.W.3d 213, 236-41 (Tex.App.-Fort Worth 2004, pet. denied) (setting .aside judgment against physician and hospital where patient first presented for treatment after preexisting delay in diagnosis beyond 72-hour period where surgery is effective, because delay caused probability of surgical correction to drop below 50%).

. As the Court explains, the Early Treatment for Retinopathy of Prematurity or ETROP study was conducted prior to 2003. Dr. Good was the chair of the ETROP study. Because Dr. Good was the chair of the ETROP study, the jury may have found his testimony that defendants breached the applicable standards of care particularly credible.

. As the Court points out, Dr. Good agreed that the ETROP study was not designed to determine whether a delay in screening actually affected a baby's vision, and that it would be “an incorrect use” of the ETROP study to “claim that it was designed to detect or to look at the effect of delay.” Opinion at 15-16. As Dr. Good explained, however, the result of the ETROP study was “that earlier treatment in high-risk babies had a beneficial effect compared to conventional management,” including benefits in both structure (such as retinal detachment) and function (visual acuity). The earlier study on which defendants rely specifically warned that blindness could result from a delay in either diagnosis or treatment.

. For example, during deliberations, the jury asked for a copy of the 2001 standards on which the defendants relied to establish the standards of care at the time of Daniella’s birth and treatment. The parties agreed to provide Court’s Exhibit 3, guidelines developed jointly by the American Academy of Pediatrics, the American Association for Pediatric Ophthalmology and Strabismus, and the American Academy of Ophthalmology in 2001, which provided in part,

Responsibility for examination and followup of infants at risk for ROP must be carefully defined by each neonatal intensive care unit.... If responsibility for arranging follow-up after discharge is delegated to the parents, it must be clearly understood by the parents that blindness is a possible outcome, that there is a critical time window to be met if treatment is to be successful, and that timely follow-up examination is essential to successful treatment. (Emphasis added.)

. The Court calculates this percentage from testimony at trial regarding the ETROP study. See Opinion at 16 n.23.

. Where multiple negligent actors participate in an episode leading to a single injury, the common law responded with a variety of answers ranging from denying recovery, to shifting the burden to the defendants, to simply leaving all defendants fully and jointly liable for the injury. PROSSER & KEETON ON TORTS § 52 (5th ed.1984). The Texas Supreme Court settled on the latter approach. Riley v. Indus. Fin. Serv. Co., 157 Tex. 306, *93302 S.W.2d 652, 655-56 (1957), overruled in part on other grounds, McMillen v. Klingensmith, 467 S.W.2d 193, 197 (Tex.1971). Beginning in 1973, our Legislature developed a comprehensive scheme of percentage attribution that requires juries to apportion fault among all of the actors. Act of Mar. 22, 1973, 63rd Leg., R.S., ch. 28, 1973 Tex. Gen. Laws 41 ("Comparative Negligence-Contribution Among Joint Tort-Feasors”). While I concede that the negligence question as to Dr. Ponte is a closer one, the question of apportioning cause was properly resolved under Chapter 33 of the Civil Practice and Remedies Code.

. As discussed in PROSSER & KEETON ON TORTS § 41, at 266-67 (5th ed.1984), "[i]f two causes concur to bring about an event, and either one of them, operating alone, would have been sufficient to cause the identical result,” courts have applied the "substantial factor” test, that is, whether the defendant's conduct was "a material element and a substantial factor in bringing [the event] about.” The authors note "[a]n interesting occasion for application of the same principle, where the negligence of each of two parties prevents the other from being a but-for cause,” in which “A supplies B with a car with no brakes; B makes no attempt to apply the brakes; and C is hit. Or A fails to signal for a left turn; B is not looking; there is a collision, and C is injured.” Id. at 267 n.27. In such a case, the conduct of each actor is a substantial factor in bringing the event about. See id. The Texas Supreme Court also considered the distinction between but-for cause and the substantial factor test in Bostic. See Bostic, 439 S.W.3d at 342-46 (“While but for causation is a core concept in tort law, it yields to the more general substantial factor causation in situations where proof of but for causation is not practically possible or such proof otherwise should not be required.”).

. See, e.g., Tex. Penal Code Ann. § 6.04(a) (West 2011) (person is criminally responsible if result would not have occurred but for his conduct). The Legislature’s definition clearly incorporates the notion of causation in fact. See, e.g., Thompson v. State, 93 S.W.3d 16, 21 (Tex.Crim.App.2001) (evidence sufficient to support murder conviction even though victim of gunshot wound also received negligent medical care). In Thompson, the court cited a lack of evidence "that any of the actions taken in attempting to save [the victim’s] life were clearly sufficient to kill her.” Id. Under the standard of but-for causation urged by appellants in this case, however, the court in Thompson should have required the State to affirmatively prove that none of the actions taken by the victim’s doctors "were clearly sufficient to kill her” before concluding that appellant’s actions were the cause of the victim’s death.

. The Court also notes the possibility that some form of negligence might have been present among the 22% of cases in the ETROP study that experienced vision loss. That prospect suggests that the inevitability of Daniella’s blindness — the speculation at the core of the Court's conclusion — is actually reduced.

. If the state of medical science allowed a reconciliation between those who respond to timely and proper treatment and those who do not, there would be no one receiving treatment except those ordained to benefit from it. If Daniella had some discernable characteristic that put her in the 22%, one would expect that her treating physicians would have known of it as well, and avoided the pain and expense of surgery.

. While the record reveals that Daniella suffered from a variety of complicating conditions that occur in extremely premature babies, such as low birth weight, that prematurity is what put her and other similarly-situated patients at high risk of developing ROP. With no evidence to explain what percentage of the ETROP patients suffered from like complications or how, if at all, those complications might have moved the probability needle we are left with the evidence we have. As that evidence is more than nothing, I would leave the parties where they were below. Relatedly, if there was some aspect of Daniella’s condition that would have placed her at an objectively increased risk of blindness (i.e., greater than 22% or, more importantly, 50%) despite timely diagnosis and treatment, one would assume that such a condition was also within the knowledge of her treating physicians who, one would expect, would have so informed her parents before exposing Daniella to the discomfort and expense of surgery despite the higher risk.