Experts at trial can make or break a case. However, not all expert testimony is admissible. Expert testimony must meet the guidelines imposed by Federal Rule of Evidence 702 to be admissible at trial. It is the federal judge’s gatekeeping role to employ the guidelines to assess the admissibility of expert witness testimony.

Effective Dec. 1, 2023, FRE 702 was amended due to a growing concern that some federal judges were allowing unreliable expert testimony to be admitted mostly because they were not properly applying the guidelines.¹ In that regard, the amendment was portrayed not as a change but simply a clarification. In the months since it took effect, the rule’s impact has been immediate.

Notably, appellate and trial courts are paying close attention to the amended rule and citing it in opinions, which likely means it is serving its purpose — uniform application of the admissibility requirements of FRE 702 when expert testimony is challenged. This article looks at the impact of the amendment on federal appellate and trial courts and provides tips and tools for practitioners as they encounter it in practice.

FRE 702 HISTORY

In 1975, Congress issued the Federal Rules of Evidence to provide a standard for the use of expert witness testimony. In 1993, the U.S. Supreme Court granted certiorari in Daubert v. Merrell Dow Pharmaceuticals and addressed whether expert evidence and testimony should be generally accepted or meet some other set of requirements.² In Daubert, the Court charged trial judges with the responsibility of acting as gatekeepers to exclude unreliable expert testimony and set forth a non-exclusive checklist for trial courts to use in assessing the reliability of scientific testimony.

Later, in Kumho Tire Co. v. Carmichael,³ the Court “clarified that this gatekeeper function applied to all expert testimony, not just testimony based on science.”⁴ Over the last 20 years, despite a 2000 amendment to codify guidelines set forth in Daubert and Kumho Tire, there has been a growing concern that FRE 702 has not been properly administered by some federal judges, enough to warrant the 2023 amendment.

AMENDED FRE 702

Last year, FRE 702 was amended in two ways. First, it was changed to make clear that the preponderance of evidence standard applies to the assessment of whether expert witness testimony meets the admissibility requirements of FRE 702.⁵ Second, the rule was amended to clarify to trial courts that expert opinions must be reliable to be admissible. In other words, trial courts must assess whether the opinion is “within the bounds of what can be concluded from a reliable application of the expert’s basis and methodology.”⁶ Trial courts cannot simply let the jury determine if expert testimony is reliable, which was what was happening in some cases.

Whether these changes will correct the misapplication of the rule by trial courts will take time to assess. Likewise, whether the amendment will lead to unintended increased scrutiny of expert witnesses will also be borne out over time. In the months since the rule took effect, appellate and trial courts — as well as attorneys — are most certainly paying attention to it.

AMENDED FRE 702’S IMMEDIATE IMPACT

Scrutiny of Pre-Amendment Daubert decisions

Since the amendments took effect, appellate courts have been reviewing trial courts’ Daubert rulings with added emphasis on whether the correct standard was used to ascertain the admissibility of expert testimony and the reliability of methods used by the expert. In re Onglyza and Kombiglyze Products Liability Litigation is a multidistrict class action litigation alleging that certain diabetes drugs can cause heart failure.⁷ With the amendments to FRE 702 at the forefront of its analysis, the U.S. Sixth Circuit Court of Appeals examined whether the trial court correctly excluded testimony of the plaintiffs’ proffered expert. The plaintiffs’ expert concluded that a causal link existed between the drug and heart failure and relied on only one study which did not find causation, but a statistical significance. The trial court found the expert testimony unreliable because it simply inferred a causal link without pointing to studies of causation. The court also criticized the expert’s cherry-picking of some of the factors of causation instead of addressing and applying all of the factors, which is the industry standard. The trial court also found the expert’s use of animal data unreliable due to his inexperience in interpreting it. The plaintiff’s attorney appealed the trial court ruling excluding the testimony. The court of appeals affirmed, finding that the trial court correctly applied FRE 702 as amended by examining the expert’s methodologies to conclude that his testimony did not meet the preponderance of evidence standard.

Some trial courts, perhaps with their eyes on potential appellate review, have even begun to rethink their own previous Daubert rulings and have called for a do-over of Daubert motions and hearings.

One of the most notable cases impacted by the amended FRE 702 is the Johnson & Johnson talcum powder multi-district litigation, which began in 2016 and has grown to involve around 53,000 plaintiffs.⁸ The court agreed to bifurcate the case to focus on the causation element first since resolving that element could mean dismissal. The parties spent more than a year engaging in expert discovery and submitted thousands of pages in Daubert briefs followed by an eight-day Daubert hearing. The court then issued its 141-page opinion in April 2020 in which it dove into the Daubert factors and ultimately decided to preclude some of the proffered experts from testifying regarding certain issues.⁹

In her Daubert opinion, Chief Judge Freda L. Wolfson, who has since retired from the federal bench, did a deep dive into the experts, their backgrounds, reports, and testimonies and did not shy away from weighing the evidence each of them offered. Although the court cited the correct standard that “[t]he proponent bears the burden of establishing admissibility by a preponderance of the evidence,” the court went on to apply that standard to the weight of the evidence rather than the admissibility of the expert testimony.¹⁰ For example, the court held that one of the plaintiffs’ experts was not permitted to testify as to whether there is a causal link between use of talcum powder and ovarian cancer.¹¹ In reaching this conclusion, the court examined in detail the expert’s in vitro study and compared it to his deposition testimony, finding it to be “damning to his own conclusion.”¹² In other words, the court rendered the expert’s testimony unreliable by impeaching him using his deposition.

The case proceeded through its natural trajectory and the parties’ experts either provided new reports or amended their original ones based on the court’s Daubert opinion — that is, until March 27, 2024, when the court issued a text-only order directing “a full refiling of Daubert motions [due to] recent changes to Federal Rule of Evidence 702, the emergence of new relevant science, and the language of Chief Judge Wolfson’s previous Daubert opinion.”

In another case, Coblin v. Depuy Orthopaedics, Inc,¹³ the trial court cited the amendment to FRE 702 and allowed the plaintiff’s expert to revise his report for another round of Daubert motions. Specifically, the expert, a pathologist, failed to address any of the defendants’ alternate cause of death theories in his report. Relying on Sixth Circuit precedent, the trial court held that while an expert need not address every other conceivable cause of death, he or she must fulfill the rule-out requirement by providing “a reasonable explanation as to why ‘he or she has concluded that any alternative cause suggested by the defense was not the sole cause.’”¹⁴ These cases suggests that trial courts may, for some short period of time, allow litigants the opportunity to correct or supplement flawed expert reports or findings proffered pre-amendment.

Trial Court Application

In addition to reviewing their previous Daubert decisions, trial courts are increasingly making note of the amendments in their new Daubert decisions and analyzing whether a party’s challenges go to weight versus admissibility with a more critical lens. Rather than just mentioning the amendment to the rule in the legal standard section of their opinions, courts appear to be paying closer attention to the expert’s methodologies and are careful of slipping into the rabbit hole of weighing evidence on the jury’s behalf.

In CSX Transportation, Inc v. Zayo Group, LLC, the trial court interpreted the amendments to impose an additional task of ensuring that “the proponent has made the requisite showing under the ‘more likely than not’ standard.”¹⁵ Using the preponderance of the evidence standard, the CSX Transportation court concluded that the plaintiff failed to show its expert was more likely than not to meet the reliability requirements under 702.¹⁶ In addition to examining the methods used by the proposed expert, the court looked at whether the proposed expert used reliable information and was critical of his failure to apply industry standards to reach his conclusion or provide evidence to support his opinion.¹⁷ The expert in this case had access to various materials exchanged in discovery “and a reliable methodology would have consisted of using that information” to reach his conclusion.¹⁸ However, without citing to any evidence, the expert’s conclusions were deemed mere speculations and baseless assumptions.¹⁹ Thus, the expert’s testimony did not meet the preponderance of evidence standard of admissibility.

Despite the clarification the amended FRE 702 provides, some litigants continue to take a “kitchen sink” approach to their Daubert challenges and attack the weight of the expert’s testimony rather than its admissibility. Litigants defending against Daubert challenges should be careful of these tactics, as they can be used to try to confuse the court into conflating weight and admissibility.

In Maney et al v. Oregon et al, the defendants argued that the plaintiffs’ expert had “reviewed an insufficient subset of discovery provided by counsel, skimmed some documents, did not review other relevant documents, and failed to conduct an independent investigation,” and therefore, his testimony was inadmissible.²⁰ Citing the FRE 702 amendment and finding the expert had “reviewed a significant number of documents in forming his opinion and adequately identified the documents upon which he relied,” the trial court disagreed and refused to exclude his testimony merely because he reviewed only a subset of the discovery conducted.²¹ The court further concluded that the defendants’ challenges “go to the weight of his opinion, not its admissibility” and, therefore, were not grounds for exclusion under FRE 702.

In May, the U.S. District Court for the Eastern District of Michigan issued the first of a series of opinions regarding the admissibility of expert testimony in the Bellwether III case involving the Flint water crisis.²² The court highlighted that the preponderance of proof standard applies to whether the expert meets the FRE 702 factors, not to the weight of the proffered testimony. The court then dissected the defendants’ objections and compared them to the expert’s proffered testimony and isolated any credibility-based objections that were more appropriately addressed via cross examination rather than a Daubert challenge.

Similarly, in AFT Michigan v. Project Veritas, the U.S. District Court for the Eastern District of Michigan rejected a challenge to a damages expert where the defendants asserted the expert’s opinion was “unreliable and inadmissible” because it was based on estimated figures rather than accurate numbers.²³ The court determined that although the figures were technically estimates, they were reliable under the circumstances because accurate numbers were not available. The court opined that the “proper method for [d]efendants to challenge that opinion is to identify for the jury the facts and circumstances that undermine their probable amount” and that the opinion was not considered unreliable under FRE 702.

PRACTICE TIPS AND CONSIDERATIONS

Anticipating that the amendment will increase the likelihood that federal trial courts will closely scrutinize whether an expert’s trial testimony reflects a reliable application of the principles and methods to the facts of the case (as we’ve already begun to see), trial practitioners must now reconsider how they prepare expert witnesses. First, expert witnesses must be carefully selected. In addition, an expert’s application of reliable methodologies must closely align with the facts of the case. In other words, the methodology must be reliably applied to the facts. Moreover, attorneys should advise experts of the amended rule at the time of engagement and review with them the burden of proof regarding admissibility.

Attorneys should also ensure that the expert is able to defend their opinions in light of the amendment to FRE 702. When objecting to expert witness testimony, motions filed with the court should remind the court of the preponderance standard required by FRE 702. Further, trial attorneys should make certain to avoid citing outdated precedent in briefings and arguments that may distract the court or tarnish credibility.

CONCLUSION

The amended FRE 702 was not designed to create a more arduous threshold for having an expert’s trial testimony deemed admissible. It was designed to create a more uniform application of the rule by federal trial courts and prevent its misapplication. The amendment may even encourage filing of more Daubert motions by litigants. Regardless, the need to understand the amendment and the court’s gatekeeper role under it is key to success when challenging or defending expert testimony.