Chapter 18 Preparing a Challenge to the Admissibility of Expert Testimony in the Federal and State Courts of New York

• Jurisdiction: New York

CHAPTER EIGHTEEN PREPARING A CHALLENGE TO THE ADMISSIBILITY OF EXPERT TESTIMONY IN THE FEDERAL AND STATE COURTS OF NEW YORK* J. Peter Coll, Jr., Esq.
Christopher P. Johnson, Esq.
Kathryn S. Bevilacqua, Esq.

I. INTRODUCTION

Although products liability claims may vary significantly from case to case, one element common to every products liability case is expert testimony. Whether it be testimony about the alleged defect in the product, the nature of the injury suffered by a plaintiff or the causative link between the two, products liability cases typically involve technical, scientific or medical issues that are beyond the ken of the average layperson and require expert opinion evidence ³²¹¹

Because of concern over “junk science” and other suspect “expert” testimony ³²¹² many products liability practitioners began in the 1980s to scrutinize closely and, where appropriate, to challenge the admissibility of proffered expert testimony. Following the U.S. Supreme Court’s landmark 1993 decision in Daubert v. Merrell Dow Pharmaceuticals, Inc ³²¹³ challenges to the admissibility of expert opinion evidence have become a standard aspect of products liability practice.

This chapter addresses several issues regarding challenges to the admissibility of expert opinion testimony in the federal and state courts of New York. First, the standards governing the admissibility of expert testimony in federal and New York state courts are identified. Following that is a discussion of how to obtain and use expert discovery in New York federal and state courts to mount the expert challenge. This section includes a review of both the expert discovery rules in the Federal Rules of Civil Procedure (as applied in the four federal districts in New York), as well as the more limited expert discovery permitted under New York State’s Civil Practice Law and Rules. Finally, the procedural options available for asserting the expert challenge are addressed.

In general, the practitioner should realize that the ability to assert the expert challenge in New York’s federal courts is made possible by the expansive expert discovery rules in Federal Rules of Civil Procedure 26 (FRCP) and the well-defined expert admissibility standards in Federal Rules of Evidence 702 and 703 (FRE). Because there is very limited expert discovery in New York state courts and because the equivalent New York state admissibility standards are not well defined, it is significantly more difficult to assert the expert challenge in New York state courts. ³²¹⁴

II. FEDERAL AND STATE STANDARDS REGARDING THE ADMISSIBILITY OF EXPERT TESTIMONY

Three basic, independent criteria govern the admissibility of expert opinion testimony in federal and state courts: established expertise, the reliability of the opinion and the reliability of the data supporting the opinion. Both federal and New York state courts consider the qualifications of the expert witness, but the federal courts tend to scrutinize the asserted expertise in a more exacting fashion. The reliability of the methodology employed by the qualified expert (sometimes couched in terms of “helpfulness” to a lay jury) is the principal criterion used in federal court—a result of the U.S. Supreme Court’s decision in Daubert. ³²¹⁵ While New York state trial courts also reference a “helpfulness” standard, there has been little elucidation of that standard and it has not been equated to the Daubert standard. Finally, both New York’s federal and state courts consider the reliability of the data upon which an expert predicates an opinion but, again, the federal courts appear to pay more careful attention to that factor than do New York state courts.

A. Reliability of Methodology

As noted earlier, Daubert both established reliability as the principal standard for assessing expert admissibility in the federal courts and provided an analytical framework for the expert challenge by identifying certain criteria as relevant to ascertaining reliability. In contrast, the New York state civil courts have no concrete analytical framework for evaluating the reliability of expert opinion evidence.

1. The Federal Standard

Daubert was the U.S. Supreme Court’s first analysis of the evidentiary rules governing the admissibility of expert testimony. The FRE, enacted by Congress in 1975, devote an entire article to “Opinions and Expert Testimony” and include six rules that cover topics such as “Bases of Opinion Testimony by Experts,” ³²¹⁶ “Opinion on an Ultimate Issue” ³²¹⁷ and “Court-Appointed Expert Witnesses.” ³²¹⁸ Of particular significance is FRE 702 regarding “Testimony by Expert Witnesses,” which provides as follows: “If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.” ³²¹⁹

Daubert involved the admissibility of expert opinion evidence in a Bendectin products liability case. During the 1980s, scores of cases alleged that Bendectin, a prescription anti-nauseant used during pregnancy, caused fetal limb defects. In light of such claims, dozens of epidemiological studies were conducted to investigate whether Bendectin is a human teratogen (i.e., a substance that causes birth defects in humans). Each of those published studies concluded that there was no statistically significant association between the use of Bendectin during pregnancy and birth defects.

Faced with this negative human data, the plaintiffs in Daubert sought to prove causation through expert opinions based upon a “re-analysis” of the existing negative epidemiological studies, in vivo and in vitro animal tests and chemical structure analyses. On the defendants’ motion, the U.S. District Court for the Southern District of California held that the plaintiff’s expert opinion evidence was inadmissible under FRE 703 and FRE 403. ³²²⁰ The court, however, did not analyze either of those rules. ³²²¹ The court then concluded that, without the contested expert opinion evidence, the plaintiffs could not create a genuine issue of material fact with respect to causation, and granted summary judgment to the defendants. ³²²²

On appeal, the U.S. Court of Appeals for the Ninth Circuit, without any substantive discussion of FRE 702 or 703, ³²²³ held that, under the test established in 1923 in Frye v. United States, ³²²⁴ scientific expert opinion is admissible only if the scientific methodology underlying the opinion is “generally accepted” as reliable within the scientific community. ³²²⁵ Finding that the plaintiff’s experts had reached their opinions by using methodologies that diverged from those “generally accepted” in the scientific community, the Ninth Circuit affirmed the district court’s grant of summary judgment.

By ignoring the FRE in favor of Frye’s “general acceptance” test, the Ninth Circuit implicitly (but necessarily) decided that Frye had survived the 1975 enactment of the FRE. This precise issue had engendered a split among the federal circuits. ³²²⁶ To resolve this split, the U.S. Supreme Court granted certiorari in Daubert, held that the FRE had superseded Frye and established a rule of expert opinion admissibility based squarely upon the language of FRE 702. ³²²⁷

The Supreme Court ruled that, when faced with a proffer of expert scientific evidence, a federal judge must act as a “gatekeeper” to ensure that the scientific expert testimony satisfies FRE 702. Specifically, the Court held that FRE 702’s “scientific knowledge” requirement establishes a standard of “evidentiary reliability”—or “trustworthiness”—that expert opinion evidence must satisfy before admission. ³²²⁸ “Scientific” implies a grounding in the methods and procedures of science. “Knowledge,” meanwhile, is more than a witness’s subjective belief or unsupported speculation. ³²²⁹ Thus, according to the Court, to determine evidentiary reliability, the gatekeeper’s focus must be based upon a finding of scientific validity. ³²³⁰

The Daubert Court discussed appropriate, but not dispositive or exclusive, factors for a trial court to consider in evaluating scientific validity:

1. whether the theory “can be (and has been) tested”;

2. whether the theory has been subjected to peer review;

3. the “known or potential rate of error” in application of the theory; and

4. whether there is an “explicit identification of a relevant scientific community and an express determination of a particular degree of acceptance within that community.”³²³¹

In addition to finding a standard of scientific validity in FRE 702, the Supreme Court also held that FRE 702 contains a standard of relevance, or “fit.” Specifically, the Court noted that FRE 702 requires that expert opinion evidence “assist the trier of fact to understand the evidence or to determine a fact in issue.” ³²³² According to the Court, this language “goes primarily to relevance” and “requires a valid scientific connection to the pertinent inquiry as a precondition to admissibility.” ³²³³ The “fit” analysis has been succinctly described as follows

• [A] plaintiff will not be able to succeed in a toxic tort case unless he or she can prove adequate exposure to a toxic substance that was somehow connected to the defendant. Even if an expert testifies that Substance X can cause the plaintiff’s injury, this testimony will not suffice if the plaintiff failed to produce evidence that he or she was exposed to Substance X, or to a specific defendant’s Substance X, or at a significant level.³²³⁴ In short, Daubert required the federal judiciary to enter a “brave new world”³²³⁵ of exploring, evaluating and confirming the objective scientific validity of a proffered expert opinion before admitting that opinion into evidence. Aided by texts such as...