The Misbegotten Judicial Resistance to the Daubert Revolution

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. …