Professor Michael D. Green is one of the Reporters for the American Law Institute’s Restatement (Third) of Torts: Liability for Physical and Emotional Harm. Green has been an important interlocutor in the on-going debate and discussion over standards for expert witness opinions. Although many of his opinions are questionable, his writing is clear, and his positions, transparent. The seduction of Professor Green and the Wake Forest School of Law by one of the litigation-industry’s organizations, the Center for Progressive Reform, is unfortunate, but the resulting symposium gave Professor Green an opportunity to speak and write about the justly controversial comment c. Restatement (Third) of Torts: Liability for Physical and Emotional Harm § 28, cmt. c (2010).
Mock Pessimism Over Milward
Professor Green professes to be pessimistic about the Milward decision, but his only real ground for pessimism is that Milward will not be followed. Michael D. Green, “Pessimism about Milward,” 3 Wake Forest J. L & Policy 41 (2013). Green describes the First Circuit’s decision in Milward as “fresh,” “virtually unique and sophisticated,” and “satisfying.” Id. at 41, 43, and 50. Green describes his own reaction to the decision in terms approaching ecstasy: “delighted,” “favorable,” and “elation.” Id. at 42, 42, and 43.
Green interprets Milward to embrace four comment c propositions:
- “Recognizing that judgment and interpretation are required in assessments of causation.52
- Endorsing explicitly and taking seriously weight of the evidence methodology,53 against the great majority of federal courts that had, since Joiner, employed a Balkanized approach to assessing different pieces of evidence bearing on causation.54
- Appreciating that because no algorithm exists to constrain the inferential process, scientists may reasonably reach contrary conclusions.55
- Not only stating, but taking seriously, the proposition that epidemiology demonstrating the connection between plaintiff’s disease and defendant’s harm is not required for an expert to testify on causation.56 Many courts had stated that idea, but very few had found non-epidemiologic evidence that satisfied them.57”
Id. at 50-51.
Green’s points suggest that comment c was designed to reinject a radical subjectivism into scientific judgments allowed to pass for expert witness opinions in American courts. None of the points is persuasive. Point (1) is vacuous. Saying that judgment is necessary does not imply that anything goes or that we will permit the expert witness to be the judge of whether his opinion rises to the level of scientific knowledge. The required judgment involves an exacting attention to the role of random error, bias, or confounding in producing an apparent association, as well as to the validity of the data, methods, and analyses used to interpret observational or experimental studies. The required judgment involves an appreciation that not all studies are equally weighty, or equally worthy of consideration for use in reaching causal knowledge. Some inferences are fatally weak or wrong; some analyses or re-analyses of data are incorrect. Not all judgments can be blessed by anointing some of them “subjective.”
Point (2) illustrates how far the Restatement process has wondered into the radical terrain of abandoning gatekeeping altogether. The approach that Green pejoratively calls “Balkanized” is a careful look at what expert witnesses have relied upon to assess whether their conclusions or claims follow from their relied upon sources. This is the approach used by International Agency for Research on Cancer (IARC) working groups, whose method Green seems to endorse. Id. at 59. IARC working groups discuss and debate their inclusionary and exclusionary criteria for studies to be considered, and the validity of each study and its analyses, before they get to an assessment of the entire evidentiary display. (And several of the IARC working groups have been by no means free of the conscious bias and advocacy that Green sees in party-selected expert witnesses.) Elsewhere, Green refers to the approach of most federal courts as “corpuscular.” Id. at 51. Clearly, expert witnesses want to say things in court that do not, so to speak, add up, but Green appears to want to give them all a pass.
Point (3) is, at best, a half truth. Is Green claiming that reasonable scientists always disagree? His statement of the point suggests epistemiologic nihilism. Although there are no clear algorithms, the field of science is littered with abandoned and unsuccessful theories from which we can learn when to be skeptical or dismissive of claims and conclusions. Certainly there are times when reasonable experts will disagree, but there are also times when experts on one side or the other, or both, are overinterpreting or misinterpreting the available evidence. The judicial system has the option and the obligation to withhold judgments when faced with sparse or inconsistent data. In many instances, litigation arises because the scientific issues are controversial and unsettled, and the only reasonable position is to look for more evidence, or to look more carefully at the extant evidence.
Point (4) is similarly overblown and misguided. Green states his point as though epidemiology will never be required. Here Green’s sympathies betray any sense of fidelity to law or science. Of course, there may be instances in which epidemiologic evidence will not be necessary, but it is also clear that sometimes only epidemiologic methods can establish the causal claim with any meaningful degree of epistemic warrant.
ANECDOTES TO LIVE BY
Anthony Robbins’ Howler
Professor Green delightfully shares two important anecdotes. Both are revealing of the process that led up to comment c, and to Milward.
The first anecdote involves the 2002 meeting of the American Law Institute. Apparently someone thought to invite Dr. Anthony Robbins as a guest. (Green does not tell us who performed this subversive act.) Robbins is a member of SKAPP, the organization started with plaintiffs’ counsel’s slush fund money diverted from MDL 926, the silicone-gel breast implant litigation.
Robbins rose at the meeting to chastise the ALI for not knowing what it was talking about:
“clear, in my opinion, misstatements of . . . science” or reflected a misunderstanding of scientific principles that “leaves everyone in doubt as to whether you know what you are talking about . . . .”
Id. at 44 (quoting from 79th Annual Meeting, 2002 A.L.I. PROC. at 294). Pretty harsh, except that Professor Green proceeds to show that it was Robbins who had no idea of what he was talking about.
Robbins asserted that the requirement of a relative risk of greater than two was scientifically incorrect. From Green’s telling of the story, it is difficult to understand whether Robbins was complaining about the use of relative risks (greater than two) for inferring general or specific causation. If the former, there is some truth to his point, but Robbins would be wrong as to the latter. Many scientists have opined that relative risks provide information about attributable fractions, which in turn permit inferences about individual cases. See, e.g., Troyen A. Brennan, “Can Epidemiologists Give Us Some Specific Advice?” 1 Courts, Health Science & the Law 397, 398 (1991) (“This indeterminancy complicates any case in which epidemiological evidence forms the basis for causation, especially when attributable fractions are lower than 50%. In such cases, it is more probable than not that the individual has her illness as a result of unknown causes, rather than as a result of exposure to hazardous substance.”). Others have criticized the inference, but usually on the basis that the inference requires that the risk be stochastically distributed in the population under consideration, and we often do not know whether this assumption is true. Of course, the alternative is that we must stand mute in the face of even very large relative risks and established general causation. See, e.g., McTear v. Imperial Tobacco Ltd., [2005] CSOH 69, at ¶ 6.180 (Nimmo Smith, L.J.) (“epidemiological evidence cannot be used to make statements about individual causation… . Epidemiology cannot provide information on the likelihood that an exposure produced an individual’s condition. The population attributable risk is a measure for populations only and does not imply a likelihood of disease occurrence within an individual, contingent upon that individual’s exposure.”).
Robbins second point was truly a howler, one that suggests his animus against gatekeeping may grow out of a concern that he would never pass a basic test of statistical competency. According to Green, Robbins claimed that “increasing the number of subjects in an epidemiology study can identify small effects with ‘an almost indisputable causal role’.” Id. at 45 (quoting Robbins). Ironically, lawyer and law professor Green was left to take Robbins to school, to educate him on the differences between sampling error, bias, and confounding. Green does not get the story completely right because he draws an artificial line between observational epidemiology and experimental clinical trials, and incorrectly implies that bias and confounding are problems only in observational studies. Id. at 45 n. 24. Although randomization is undertaken in clinical trials to control for bias and confounding, it is not true that this strategy always works or always works completely. Still, here we have a lawyer delivering the comeuppance to the scolding scientist. Sometimes scientists really have no good basis to support their claims, and it is the responsibility of the courts to say so. Green’s handling of Robbins’ errant views is actually a wonderful demonstration of gatekeeping in action. What is lovely about it is that the claims and their rebuttal were documented and reported, rather than being swept away in the fog of a jury verdict.
Professor Green’s account of Robbins’ foolery should be troubling because, despite Robbins’ manifest errors, and his more covert biases, we learn that Robbins’ remarks had “a profound impact” on the ALI’s deliberations. Courts that are tempted by the facile answers of comment c should find this impact profoundly disturbing.
Alan Done’s Weight of the Evidence (WOE) or Mosaic Methodology
Professor Green relays an anecdote that bears repeating, many times. In the Bendectin litigation, plaintiffs’ expert witness, Alan Done testified that Bendectin caused birth defects in children of mothers who ingested the anti-nausea medication during pregnancy. Done had a relatively easy time spinning his speculative web in the first Bendectin trial because there was only one epidemiologic study, which qualitatively was not very good. In his second outing, Done was confronted by the defense with an emerging body of exonerative epidemiologic research. In response, he deployed his “mosaic theory” of evidence, of different pieces or lines of evidence that singularly do not show much, but together paint a conclusive picture of the causal pattern. Id. at 61 (describing Done’s use of structure-activity, in vitro animal studies, in vivo animal studies, and his own [idiosyncratic] interpretation of the epidemiologic studies). Done called his pattern a “mosaic,” which Green correctly sees is none other than “weight of the evidence.” Id. at 62.
After this second trial was won with the jury, but lost on post-trial motions, plaintiffs’ counsel, Barry Nace, pressed the mosaic theory as a legitimate scientific strategy to demonstrate causation, and the appellate court accepted the strategem:
“Like the pieces of a mosaic, the individual studies showed little or nothing when viewed separately from one another, but they combined to produce a whole that was greater than the sum of its parts: a foundation for Dr. Done’s opinion that Bendectin caused appellant’s birth defects. The evidence also established that Dr. Done’s methodology was generally accepted in the field of teratology, and his qualifications as an expert have not been challenged.103”
Id. at 61(citing Oxendine v. Merrell Dow Pharm., Inc., 506 A.2d 1100, 1110 (D.C. 1986). Green then drops his bombshell: the philosopher of science who developed the “mosaic theory” (WOE) was the plaintiffs’ lawyer, Barry Nace. According to Green, Nace declared the mosaic idea “Damn brilliant, and I was the one who thought of it and fed it to Alan [Done].” Id. at 63.
Green attempts to reassure himself that Milward does not mean that Done could use his WOE approach to testify today that Bendectin causes human birth defects. Id. at 63. Alas, he provides no meaningful solution to protect against future bogus cases. Green fails to come to grips with the obvious truth that Done was wrong ab initio. He was wrong before he was exposed for his perjurious testimony. See id. at 62 n. 107, and he was wrong before there was a “solid body” of exonerative epidemiology. His method never had the epistemic warrant he claimed for it, and the only thing that changed over time was a greater recognition of his character for veracity, and the emergence of evidence that collectively supported the null hypothesis of no association. The defense, however, never had the burden to show that Done’s methodology was unreliable or invalid, and we should look to the more discerning scientists who saw through the smokescreen from the beginning.
