Although the plaintiffs, in Matrixx Intiatives, Inc. v. Siracusano, generally were accurate in defining statistical significance than the defendant, or than the so-called “statistical expert” amici (Ziliak and McCloskey), the plaintiffs’ brief goes off the rails when it turned to discussing the requirements for proving causation. Of course, the admissibility and sufficiency of evidence to show causation were not at issue in the case, but plaintiffs got pulled down the rabbit hole dug by the defendant, in its bid to establish a legal bright-line rule about pleading.
Differential Diagnosis
In an effort to persuade the Court that statistical significance is not required, the plaintiffs/respondents threw science and legal principles to the wind. They contended that statistical significance is not at all necessary to causal determinations because
“[c]ourts have recognized that a physician’s differential diagnosis (which identifies a likely cause of certain symptoms after ruling out other possibilities) can be reliable evidence of causation.”
Respondents’ Brief at 49. Perhaps this is simply the Respondents’ naiveté, but it seems to suggest scienter to deceive. Differential diagnosis is not about etiology; it is about diagnosis, which rarely incorporates an assessment of etiology. Even if the differentials were etiologies and not diagnoses, the putative causes in the differential must already be shown, independently, to be capable of causing the outcome in question. See, e.g., Tamraz v. Lincoln Electric Co., 620 F.3d 665 (6th Cir. 2010). A physician cannot rule in an etiology in a specific person simply by positing it among the differentials, without independent, reliable evidence that the ruled in “specific cause” can cause the outcome in question, under the circumstances of the plaintiff’s exposure. Furthermore, differential diagnosis or etiology is nothing more than a process of elimination to select a specific cause; it has nothing to do with statistical significance because it has nothing to do with general causation.
This error in the Respondent’s brief about differential diagnosis unfortunately finds its way into Justice Sotomayor’s opinion.
Daubert Denial and the Recrudescence of Ferebee
In their zeal, the Respondents go further than advancing a confusion between general and specific causation, and an erroneous view of what must be shown before a putative cause can be inserted in a set of differential (specific) causes. They cite one of the most discredited cases in 20th century American law of expert witnesses:
“Ferebee v. Chevron Chem. Co., 736 F.2d 1529, 1536 (D.C. Cir. 1984) (“products liability law does not preclude recovery until a ‘statistically significant’ number of people have been injured”).”
Respondents’ Brief at 50. This is not a personal, subjective opinion about this 1984 pre-Daubert decision. Ferebee was wrongly decided when announced, and it was soon abandoned by the very court that issued the opinion. It has been a derelict on the sea of evidence law for over a quarter of a century. Citing to Ferebee, without acknowledging its clearly overruled status, raises an interesting issue about candor to the Court, and the responsibilities of counsel in trash picking in the dustbin of expert witness law.
Along with its apparent rejection of statistical significance, Ferebee is known for articulating an “anything goes” philosophy toward the admissibility and sufficiency of expert witnesses:
“Judges, both trial and appellate, have no special competence to resolve the complex and refractory causal issues raised by the attempt to link low-level exposure to toxic chemicals with human disease. On questions such as these, which stand at the frontier of current medical and epidemiological inquiry, if experts are willing to testify that such a link exists, it is for the jury to decide to credit such testimony.”
Ferebee v. Chevron Chemical Co., 736 F.2d 1529, 1534 (D.C. Cir.), cert. denied, 469 U.S. 1062 (1984). Within a few years, the nihilism of Ferebee was severely limited by the court that decided the case:
“The question whether Bendectin causes limb reduction defects is scientific in nature, and it is to the scientific community that the law must look for the answer. For this reason, expert witnesses are indispensable in a case such as this. But that is not to say that the court’s hands are inexorably tied, or that it must accept uncritically any sort of opinion espoused by an expert merely because his credentials render him qualified to testify… . Whether an expert’s opinion has an adequate basis and whether without it an evidentiary burden has been met, are matters of law for the court to decide.”
Richardson v. Richardson-Merrell, Inc., 857 F.2d 823, 829 (D.C. Cir. 1988).
Of course, several important decisions intervened between Ferebee and Richardson. In 1986, the Fifth Circuit expressed a clear message to trial judges that it would no longer continue to tolerate the anything-goes approach to expert witness opinions:
“We adhere to the deferential standard for review of decisions regarding the admission of testimony by xperts. Nevertheless, we … caution that the standard leaves appellate judges with a considerable task. We will turn to that task with a sharp eye, particularly in those instances, hopefully few, where the record makes it evident that the decision to receive expert testimony was simply tossed off to the jury under a ‘let it all in’ philosophy. Our message to our able trial colleagues: it is time to take hold of expert testimony in federal trials.”
In re Air Crash Disaster, 795 F.2d 1230, 1234 (5th Cir. 1986) (emphasis added).
In the same intervening period between Ferebee and Richardson, Judge Jack Weinstein, a respected evidence scholar and well-known liberal judge, announced :
“The expert is assumed, if he meets the test of Rule 702, to have the skill to properly evaluate the hearsay, giving it probative force appropriate to the circumstances. Nevertheless, the court may not abdicate its independent responsibilities to decide if the bases meet minimum standards of reliability as a condition of admissibility. See Fed. Rule Ev. 104(a). If the underlying data are so lacking in probative force and reliability that no reasonable expert could base an opinion on them, an opinion which rests entirely upon them must be excluded.”
In re “Agent Orange” Prod. Liab. Litig., 611 F. Supp. 1223, 1245 (E.D.N.Y. 1985)(excluding plaintiffs’ expert witnesses), aff’d, 818 F.2d 187 (2d Cir. 1987), cert. denied, 487 U.S. 1234 (1988).
The notion that technical decisions had to be evidence based, not opinion based, emerged elsewhere as well. For example, in the context of applying statistics, the federal courts pronounced that the ipse dixit of parties and witnesses did not count for much:
“When a litigant seeks to prove his point exclusively through the use of statistics, he is borrowing the principles of another discipline, mathematics, and applying these principles to the law. In borrowing from another discipline, a litigant cannot be selective in which principles are applied. He must employ a standard mathematical analysis. Any other requirement defies logic to the point of being unjust. Statisticians do not simply look at two statistics, such as the actual and expected percentage of blacks on a grand jury, and make a subjective conclusion that the statistics are significantly different. Rather, statisticians compare figures through an objective process known as hypothesis testing.”
Moultrie v. Martin, 690 F.2d 1078, 1082 (4th Cir. 1982)(citations omitted)
Of course, not long after the District of Columbia Circuit decided Ferebee, in 1993, the Supreme Court decided Daubert, followed by decisions in Joiner, Kumho Tire, and Weisgram. In 2000, Congress approved a new Rule of Evidence 702, which incorporated the learning and experience in judicial gatekeeping from a wide range of cases and principles.
Do the Respondents have a defense to having cited an overruled, superseded, discredited precedent in the highest federal Court? Perhaps they would argue that they are in pari delicto with courts (Daubert-Deniers), which remarkably have ignored the status of Ferebee, and cited it. See, e.g., Betz v. Pneumo Abex LLC, 998 A.2d 962, 981 (Pa. Super. 2010); McCarrell v. Hoffman-La Roche, Inc., 2009 WL 614484, *23 (N.J.Super.A.D. 2009). See also Rubanick v. Witco Chemical Corp., 125 N.J. 421, 438-39 (1991)(quoting Ferebee before it was overruled by the Supreme Court, but after it was disregarded by the D.C. Circuit in Richardson).
