The misbegotten judicial resistance to the Daubert revolution.

• Author: Bernstein, David E.

INTRODUCTION

Until approximately thirty years ago, expert witnesses hired by parties to litigation in the United States could testify almost without limit about any relevant issue within the scope of their expertise. (1) Beginning in the mid-1980s, federal law rapidly and radically evolved until by 2000 all expert testimony needed to pass a reliability test before it could be deemed admissible. (2) Much of this evolution took place in toxic tort cases, in the context of broader debate about the efficiency and justice of toxic tort litigation. (3) Controversy surrounded mass tort litigation involving the morning sickness drug Bendectin, silicone gel breast implants, and the herbicide Agent Orange, among other products and substances. (4)

Many courts ultimately determined that much of this litigation relied on causation theories that were not supported by sound scientific evidence. This led to judicial rulings restricting the admissibility of expert testimony, which in turn created sufficient uncertainty and controversy to provoke Supreme Court intervention. (5) In a period of six years, the Supreme Court issued the so-called Daubert trilogy of opinions--Daubert v. Merrell Dow Pharmaceuticals, Inc., (6) General Electric Co. v. Joiner, (7) and Kumho Tire Co. v. Carmichael (8)--each of which tightened the standards for the admissibility of expert testimony. (9) In 2000, an amendment to Federal Rule of Evidence 702 codified a test that allows experts to testify only when their opinions meet a stringent reliability test. (10)

The profound changes to the traditional laissez-faire law of expert testimony provoked resistance from some federal judges who favored more liberal rules of admissibility. These judges rejected the early precedents excluding expert testimony from toxic torts cases of the late 1980s, (11) applied Daubert narrowly in the mid-1990s, (12) and, in the late 1990s, exploited loopholes and ambiguities in Joiner and Kumho Tire to admit questionable expert testimony. (13) All of these actions, while broadly contrary to the trajectory of expert evidence law, were within the bounds of a reasonable interpretation of the extant law.

Judicial resistance should have withered away, however, after the 2000 amendment to Federal Rule of Evidence 702. The rule provides that expert testimony that would otherwise be helpful to the jury is admissible only when (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case. (14)

To get a sense of the dramatic shift amended Rule 702 represents, just a decade before it went into effect no American jurisdiction applied such strict admissibility criteria. Most federal courts, recognizing their place in the scheme of things, (15) have acquiesced to the new regime. There has, however, been an extraordinary undercurrent of rebellion by a minority of federal judges who implicitly object to the radical changes (16) wrought by the "Daubert revolution." These judges ignore the text of Rule 702, and instead rely on lenient precedents that predate (and conflict with) not only the text of amended Rule 702, but also with some or all of the Daubert trilogy. (17)

The most prominent example of such judicial truculence is the First Circuit's 2011 opinion in Milward v. Acuity Specialty Products Group, Inc. (18) In Milward, the First Circuit reversed as an abuse of discretion a district court's ruling excluding causation evidence in a toxic tort case. (19) In doing so, the appellate court ignored Rule 702, disregarded the Supreme Court's opinion in Joiner, relied on obsolete precedents, misunderstood the underlying rationale for exclusionary rules for expert testimony, misapplied basic scientific concepts, and credulously endorsed "weight of the evidence" as a valid scientific methodology. (20)

Not surprisingly, plaintiffs' lawyers have greeted Milward with great enthusiasm, treating the opinion as a jurisprudential Moses that will part the Rule 702 Sea and lead them to the Promised Land of pre-Daubert admissibility rules. (21) Defense lawyers, meanwhile, have been aghast. (22) The Supreme Court refused to review Milward, (23) so it remains good law in the First Circuit, requiring district court judges to admit speculative causation testimony. Milward also has the potential to influence the law in other circuits and in state courts. (24)

This Article reviews the history of the evolution of the rules for the admissibility of expert testimony since the 1980s, the revolutionary nature of what ultimately emerged, and the consistent efforts by recalcitrant judges to stop or roll back the changes, even after Rule 702 was amended to explicitly incorporate a strict interpretation of those changes.

Part I reviews the law of expert testimony through the Supreme Court's Daubert decision. Critics had charged for decades that the adversarial system was a failure with regard to expert testimony. Parties to litigation, they argued, often presented expert testimony of dubious validity because it supported their positions, while lay juries were incapable of discerning which side had the better case. But it took the rise of toxic tort litigation based on questionable causation theories and the attendant threat to multi-billion dollar industries to provoke a meaningful response from the courts--a sudden and dramatic shift toward stricter admissibility standards.

Part II describes the Daubert trilogy and the emergence of amended Rule 702. A pattern emerged of the Supreme Court attempting to strengthen the rules governing expert testimony, some lower courts resisting, and the Court responding by issuing a new opinion clarifying the courts' new "gatekeeping" responsibilities. Eventually, an amendment to Federal Rule of Evidence 702 codified the Daubert trilogy, and did so with language that removed ambiguities and loopholes that had been exploited by judges who had been inclined to try to evade the Court's rulings.

Nevertheless, as Part III describes, some federal judges have continued to apply significantly more lenient standards for expert testimony than Rule 702 permits. They do so by ignoring the language of Rule 702, and instead relying on precedents from a bygone era. The First Circuit's Milward opinion, described in detail in Part III, demonstrates many errors and fallacies common to judges who have chosen to resist the Daubert revolution.

The underlying issue tying the history and present controversy over the admissibility of evidence in toxic tort litigation is a dispute over the underlying rationale for having special rules for the admissibility of expert testimony. Judges who favor more liberal rules for admissibility believe that the rules are meant to address only the problem of "junk science"--scientific testimony that not only falls outside the scientific mainstream, but does so in the face of well-accepted contrary evidence. (25)

More restrictive judges, by contrast, are addressing the broader problem of "adversarial bias" that results from our legal system allowing the parties to choose their own experts. Parties to litigation have a natural inclination to choose experts whose views match their theory of the case, even if those experts are outliers or hired guns. Rule 702 tries to limit this problem by insisting that experts show an objectively verifiable basis for their testimony, so that the trier of fact is not in the position of relying on the mere ipse dixit of an expert chosen solely because his views are consistent with the partisan position of a party to litigation. (26)

This Article concludes by discussing some of the factors that have led some federal judges to defy Rule 702. The author contends that the Supreme Court should take an appropriate opportunity to crack down on such judicial rebellion for two reasons. First, Rule 702 is the law of the land, and federal judges are obligated to enforce it regardless of their personal views on what expert testimony should be admissible. Second, Rule 702 represents a constructive effort to confront the problem of adversarial bias while retaining the basic contours of the broader adversarial process.

1. THE LAW OF EXPERT TESTIMONY THROUGH DAUBERT

   Before Daubert, American courts generally applied a very forgiving test when considering the admissibility of expert testimony. Courts required only that an expert be at least marginally qualified to testify on the subject at hand, and that his testimony be relevant to an issue in the case. (27) The only significant limitation was that the expert's testimony had to be "beyond the ken of the jury." (28)

   Even this restriction on expert testimony gradually withered. Many courts ruled that any potentially helpful expert testimony was admissible. (29) Any flaws in an expert's testimony were issues of weight, not admissibility. To the extent there were problems with an expert's methodology or reasoning, opposing counsel's only recourse was to try to alert the trier of fact to these problems at trial through cross-examination. (30) Federal Rule of Evidence 702, enacted in 1975 and eventually adopted by most states, did away with the "beyond the ken of the jury" test in favor of a helpfulness test. (31)

   These very liberal admissibility rules coexisted with deep suspicion of expert testimony. (32) Critics charged that the incentive structure facing litigants and the experts themselves made the prevalence of biased, one-sided expert testimony inevitable. (33) The underlying problem critics identified is that attorneys seeking expert witnesses do not, and have no incentive to, put-sue expertise wherever it leads. Rather, they search for an expert willing to support the litigant's position. (34) Expert testimony in the United States is therefore subject to massive adversarial bias--bias that arises because experts are hired to advance the cause...