Litigants routinely rely upon expert witnesses to provide opinion testimony at trial based on their specialized knowledge, training or experience. Also common, the opponent sees serious methodological flaws and thus reaches for a well-known weapon: a Daubert motion asking the trial court to exclude from evidence the report and any associated testimony. Originating in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) and since codified at Wis. Stat. § 907.02, such motions invoke the court’s gatekeeper function to ensure that proffered expert opinions are reliable and relevant.

Two recent decisions from the Wisconsin Court of Appeals illustrate how challenging it can be to persuade the trial court to grant such motions, let alone convince an appellate court to reverse an unfavorable decision: Vanderventer, et al. v. Hyundai Motor America, et al., No. 2020AP1052, 2022 WL 14672877 (Wis. Ct. App. Oct. 26, 2022); and Backus Electric, Inc. v. Hubbart Electric, Inc., et al., No 2019AP1651, 2022 WL 6834773 (Wis. Ct. App. Oct. 12, 2022).

Begin with Vanderventer. There, the driver in a car-crash case offered testimony from two experts to demonstrate that a design defect in the driver’s seat caused his severe injuries.

The first expert, a mechanical engineer, testified about the weakness of the seat design, especially as compared to alternate designs that Hyundai had used. But the expert had not run any tests on the allegedly defective seat. Instead, he only examined the damaged seat itself and consulted tests involving a stronger, alternate version of the seat.

The second expert was the neurosurgeon who operated on the injured driver. When presented with the first expert’s theory about the seat defect, the neurosurgeon concluded that the theory explained the spinal injuries he observed. This medical expert did not, however, examine the damaged seat or otherwise perform any testing.

Hyundai moved under Wis. Stat. § 907.02 to exclude the testimony from both experts. As to the neurosurgeon, it argued that, as a medical doctor, he did not have the expertise needed to connect what he observed during surgery to any engineering defects. And Hyundai challenged the engineer’s methodology primarily on the basis that he had merely observed but not tested the allegedly defective seat.

The trial court denied Hyundai’s motions. It pointed to the neurosurgeon’s expertise in treating spinal cord injuries and reasoned that this sufficed to support testimony about the cause of the driver’s injuries. Similarly, it found that the engineer’s testimony cleared Daubert’s low threshold since, despite the lack of testing, his conclusions amounted to more than unsupported speculation.

The court of appeals affirmed. It first helpfully summarized the general rules that govern expert testimony in Wisconsin courts. Critically, it emphasized that the reliability standard adapted from Daubert is “not exceedingly high” and merely aims at keeping out “junk science” and “conjecture.” 2022 WL 14672877, at *13. Exclusion is not appropriate for “shaky but admissible” expert testimony; rather, the remedy is “[v]igorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof.” Id. Equally important, the appellate court noted the “deferential” standard of review owed to trial courts, who have “substantial discretion” when acting as an expert-testimony gatekeeper under Wis. Stat. § 907.02. Id.

Although the engineer had concededly offered a novel theory that he had not tested on the seat at issue, the court of appeals deferred to the trial court. It found “no support in Wisconsin law” for the proposition that testing was required to establish reliability, even for “novel” theories. 2022 WL 14672877, at *16. Such a rule would be “fundamentally at odds with the flexibility and discretion trial courts have in assessing reliability.” Id. Because the engineer offered other observations that plausibly compensated for the lack of testing, the trial court had properly exercised its discretion to allow the testimony. The court of appeals also found that the engineer had sufficient expertise to connect the defective design to the injury, noting other authorities that recognized biomechanical expertise as sufficient to support opinions on the causes of injuries.

And the court of appeals rejected a similar challenge to the neurosurgeon’s testimony. His extensive experience regarding spinal injuries combined with surgical observations and the engineer’s theory yielded an admissible opinion. Medical experts may rely “predominantly, if not solely” in their “experience in the relevant field” and may “rely on facts or analysis provided by another expert.” Id. at *17. Hyundai was “free to highlight information [the neurosurgeon] overlooked or declined to obtain, calculations he did not make, and tests he did not run to diminish the persuasiveness of his opinion.” Id. at *18. But these analytical gaps did not “show that [his] testimony was merely subjective belief or unsupported speculation.” Id.

Turning to Backus Electric, this case reflects a similarly low bar to expert testimony admissibility both at the trial and appellate level. There, a business owner sued his former employee for breach of fiduciary duty when the latter allegedly purloined several of the company’s biggest customers. An accounting expert for the owner testified that the owner suffered “loss-of-business” damages, measured in part by an income valuation approach that compared the company’s revenue before and after the “precipitous” loss of valuable clients. 2022 WL 6834773, at *2.

The trial court rejected a Daubert challenge to the accountant’s testimony based on his failure to analyze “other potential factors that might have contributed to [the company’s] economic loss.” Id. Despite this analytical gap, the court reasoned that the accountant was merely “pointing out the differences in income” over two time periods, not calculating lost profits (arguably implying that the latter might have required a consideration of alternate factors).

Again, the court of appeals affirmed. Again, it emphasized the “discretionary” nature of trial-level Daubert decisions and how they must be affirmed if they have a “rational basis and [were] made in accordance with the accepted legal standards and facts of record.” Id. at *3. In a terse one-paragraph analysis, the court noted the accountant’s experience applying the income valuation approach, his explanation for using that approach to damages rather than lost profits, the availability of the underlying data he used, and the “not esoteric” nature of his analysis. Id. That alone sufficed to affirm the trial court’s Daubert ruling.

What lessons should litigators reaching for Daubert motions take from these two decisions? In a nutshell, temper your expectations. Despite arguably serious methodological flaws in the challenged expert opinions, the trial courts revealed a strong reluctance to exclude expert testimony, favoring instead to let the parties duke it out through cross-examination and competing expert testimony. Likely only a truly fatal methodological error—one that rendered the expert’s conclusion plainly wrong—would have convinced these trial courts otherwise. Similarly, the court of appeals twice exhibited an extremely deferential posture to the trial court. Absent an obvious legal error or exceptional factual oversight by the trial court, there seems to be little appetite for reversing Daubert decisions at the appellate level.

That said, given the tantalizing reward of a decision that excludes key expert evidence, even the skeptical analysis in Vanderventer and Backus Electric likely will not often dissuade litigators from reaching for this familiar weapon against shoddy expert work.

The post A Skeptical View of Daubert Motions in Two Recent Wisconsin Court of Appeals Decisions first appeared on Stafford Rosenbaum LLP.