The Pennsylvania Supreme Court recently decided Walsh v. BASF Corp., ___ A.3d ___, 2020 WL 4135151 (Pa. July 21, 2020), reaffirming product identification as an essential element of product liability.

Below, the Superior Court had turned a trial court’s routine Fryebert-like exclusion ruling in a chemical exposure case into scary new precedent in Walsh v. BASF Corp., 191 A.3d 838 (Pa. Super. 2018).  The Superior Court in Walsh reversed the exclusion of the plaintiff’s experts, holding that aggregate expert opinions that “pesticides” in general could cause “cancer” in general was both:  (1) admissible under Pennsylvania’s Frye (as opposed to Daubert)-based framework for evaluating expert testimony, and (2) sufficient to preclude summary judgment as to the chemically disparate pesticide products of fourteen different manufacturers.  Indeed, the Walsh Superior Court decision went so far as to deny that, in Pennsylvania, a trial judge had any “gatekeeping” function at all with respect to expert testimony.  Id. at 844 (“That is not the proper role of the trial court in a Frye inquiry.”).

The Superior Court in Walsh thus not only pushed back on the “bert” part of expert admissibility in Pennsylvania, but went further than ever under Frye towards letting any pro-plaintiff opinion in, regardless of its basis.

With Bexis representing a number of amici curiae, defendants in Walsh successfully obtained Pennsylvania Supreme Court review of three questions:

(1) Did the Superior Court majority commit reversible error in concluding that, when evaluating scientific evidence under the Frye standard, trial courts are not permitted to act as “gatekeepers” to ensure the relevance and reliability of scientific studies offered by experts to support their opinions by scrutinizing whether those studies actually support their opinions?

(2) Did the Superior Court majority commit reversible error in concluding that trial courts may not review experts’ opinions extrapolating from a broad class of products and injuries to a specific product and injury, thereby eliminating plaintiff’s burden to show product-specific causation of plaintiff’s specific injury?

(3) Did the Superior Court majority commit reversible error in concluding that the trial court erred without explaining how it abused its discretion because of manifest unreasonableness, partiality, prejudice, bias, ill-will or such lack of support from the evidence or the record so as to be clearly erroneous?

Walsh, 2020 WL 4135151 at *6.  Still, with the addition of four (out of seven) generally pro-plaintiff justices since 2016, the Pennsylvania Supreme Court is a difficult court for defendants these days, and the worry was that the court could inaugurate a new era of industry-wide toxic tort litigation based on the sort of product-identification-ignoring expert opinions OKed by the Superior Court in Walsh.

The Supreme Court recently decided Walsh, and by a 4-3 (or 5-2 depending on the issue) margin it affirmed the Superior Court’s result, but the basis of the affirmance was quite narrow.  Indeed, the court specifically ordered that the defendants “should be given the opportunity to renew their Frye motions for the reasons addressed in this Opinion.”  2020 WL 4135151, at *1.  All told, Walsh produced four opinions:  the majority opinion, for four justices, just cited; a concurrence by Justice Wecht, who also joined the majority, 2020 WL 4099627; a concurring and dissenting opinion by Justice Baer, who joined the majority as to issues one and three, 2020 WL 4139381; and a dissent by Chief Justice Saylor, joined by Justice Todd, 2020 WL 4139034.  We expect Westlaw to consolidate these opinions, so the numbers will probably change.  The opinions tracked the division in the court we mentioned above.  The three pre-2016 justices proved more hospitable to the defendants’ arguments, while the four post-2016 justices all lined up for affirmance – of the outcome – reached by the Superior Court, but not the reasoning.

Issue One − Gatekeeping

As to issue one, the court affirmed the Superior Court’s result while avoiding any clear ruling on trial courts as “gatekeepers.”  Walsh held that “whether a methodology is generally accepted in the relevant scientific community is a determination that has to be made based on the testimony of the scientists in that community, not upon any scientific expertise of judges.”  2020 WL 4135151, at *7.  In Walsh that “testimony” consisted of the plaintiffs’ experts, on one hand, and the defendants’ experts on the other.

[T]he trial court must be guided by scientists in the relevant field, including the experts retained by the parties in the case and any other evidence of general acceptance presented by the parties.

Id. at *8.

Conversely, trial courts may not question the merits of the expert’s scientific theories, techniques or conclusions, and it is no part of the trial court’s function to assess whether it considers those theories, techniques and/or conclusions to be accurate or reliable based upon the available facts and data.

Id.  That sounds pretty awful – like an expert can get away with anything.  But it’s not as bad as it sounds, as long as the party opposing admission (usually, but not always, our side) does its job.

What produced the nominal affirmance in Walsh was that the trial court appeared to come to its own conclusions, the majority stated, without basing those conclusions on the record before it.  “In so ruling . . . the trial court did so unilaterally, without citation to any authority or to the voluminous expert deposition testimony in the certified record.”  Id. at *9.  Frye determinations involve “scientific judgment[s] that must be guided by the experts, not a trial court.”  Id.

Given that context, it was an abuse of discretion under the Frye test for a trial court to reach a “conclusion . . . based solely upon its own analysis of the scientific studies proffered by [the expert] and not on any review of the methodology that [the expert] was utilizing.”  Id. at *10.  Thus, the Pennsylvania Supreme Court’s ruling on issue one amounts to, in practice, is an admonition to trial courts that, to exercise discretion properly, they must take care to include the necessary record citations for their rulings, and not to go beyond the grounds raised by the relevant Frye motion(s):

The trial court issued no rulings on any of [defendant’s] Frye challenges.  To the contrary . . ., the trial court did not even mention the Bradford Hill criteria. . . .  By questioning the judgment of the [plaintiff’s] experts and the reliability of their scientific conclusions, rather than focusing on whether [plaintiff] satisfied his burden of proof that [his experts] formed their opinions by application of methodologies that are generally accepted in the relevant fields of study, the trial court abused its discretion.  Accordingly, we agree with the Superior Court’s decision to vacate the trial court’s orders. . . .  On remand, the [defendants] should be afforded the opportunity to renew their Frye motions so that the relevant issues can be addressed.

Id. at *11.  Thus, no horrible substantive rulings on Frye standards were forthcoming – only the reminder not to act like federal courts do in Daubert analysis.  Cf. Id. at *7 n.6 (contrasting Frye and Daubert).  Trial courts that are careful to color within the lines (that’s the discretion point) provided by the parties’ motion practice and competing expert testimony are likely to be affirmed.  It’s OK to cite and follow a defense expert’s critique of what the plaintiff’s expert did, as long as it doesn’t appear to the trial court’s own analysis.

As for the “gatekeeper” question, the majority dodged it.  “Whether we refer to the role of the trial court in a Frye contest as that of a ‘gatekeeper’ is not consequential.  What is of consequence is the role that the trial court plays during Frye proceedings.”  Walsh, 2020 WL 4135151, at *8.  Thus, the Superior Court’s ruling disapproving of the “gatekeeper” concept was neither affirmed nor reversed, but rather shrugged off.  That’s all the majority had to say on the point.

The two concurrences (necessary to make the majority), however, are more friendly to the “gatekeeper” role.  Justice Baer concurred specifically”

to distance myself respectfully from the majority opinion to the extent it declines to recognize the trial court as “gatekeeper” in Frye challenges. . . .  [T]he gatekeeping role of the court, far from detracting from the jury’s function, is in fact essential to it as it ensures that what might appear to the jury to be science is not in fact speculation in disguise.

2020 WL 4139381, at *?, penultimate paragraph (at this point, WL has no pinpoint citations for the three non-majority opinions).

In his opinion, Justice Wecht, noted:

[T]he gatekeeper terminology is a commonplace in both Frye and Daubert case law.  Moreover, it is not inapt to say that the trial court acts as a gatekeeper in determining the admissibility of evidence generally.

2020 WL 4099627, at *? n.7 (citations and quotation marks omitted).  However, he “avoids” that “terminology, because at least colloquially it suggests a more jealously guarded portal than the Frye test calls for.”  Id.

The two-justice dissent was four-square in favor of “gatekeeping”:

The majority deems it inconsequential whether or not this Court should denominate trial judges as gatekeepers relative to the admission of novel scientific evidence in Pennsylvania courtrooms.  Personally, however, I find this to be the clear purport of most of this Court’s decisions on the subject. . . .  This Court, like most others, has implemented this particular gatekeeping responsibility in light of the influential nature of expert testimony on complex subjects and the potential that distortions have to mislead laypersons.

2020 WL 4139034, at *? (first two paragraphs) (citations omitted).

Add up the votes, and there are four (of seven members of the court) in favor of the “gatekeeper” rationale in Pennsylvania Frye determinations, at least to some extent.

So the defense didn’t really lose much on issue one.  As long as defense counsel does the kind of competent job that was done in Walsh, giving the trial court an extensive basis in the record to which it can cite for the proposition that the plaintiff’s expert’s methodology is fatally deficient, nothing much has changed, save how the Frye test should be phrased (hint – stay away from Daubert-like terminology).

Issue Two − Extrapolation

The Walsh decision on the extrapolation issue was 4-3 allowing it, with Justice Baer in full dissent.  But once again the result was explicitly limited.  The most important type of “extrapolation” – that which had the defense community concerned about new, expansive liability − was from a generalized causation opinion to multiple specific products.  As to that type of expert overreach, the Walsh majority was careful to disassociate itself entirely from the Superior Court’s reasoning:

Importantly for present purposes, however, our review of the expert reports of [plaintiff’s experts] does not reflect that either of them used extrapolation in the manner now complained of by [defendants].  Specifically, while both experts employed the Bradford Hill criteria to establish a causal link between cancer (or AML) and long-term exposure to pesticides, neither expert opined that this link wholly constituted product-specific causation between cancer and long-term exposure to the Appellants’ specific pesticide products.

2020 WL 4135151, at *12 (emphasis original).   Bexis read these reports in his amicus role in Walsh, and he’s of a different opinion, but if this is how the Pennsylvania Supreme Court wants to characterize the opinions, all the more power to it.  That, as much as anything, defangs the most worrisome part of the Superior Court’s opinion – which purported to allow a “pesticides cause cancer” opinion to extend to each of the defendants’ individual products.  See Walsh, 191 A.3d at 847 (“Although the epidemiological studies cited by [plaintiff’s] experts did not explore whether exposure to one particular pesticide product caused [the disease], we reject Defendants’ contention that such specific studies were required.”).

Thankfully, even the most pro-plaintiff members of the Pennsylvania Supreme Court were unwilling to go that far.  Instead, Walsh construed the trial court’s opinion as not even ruling on product-specific extrapolation.  2020 WL 4135151, at *12 (“[T]he trial court issued no ruling with respect to whether [plaintiff’s expert’s] failure to opine on whether the [defendants’] specific products may cause [the disease] precludes her use as an expert on general causation.”).  “As a result the Superior Court’s opinion . . . did not eliminate the plaintiff’s burden to show product-specification.”  Id.  Critically, Walsh then reaffirmed product identification as an essential element of product liability:

Pennsylvania law requires that to create a jury question, a plaintiff must adduce evidence that exposure to defendant’s [product] was sufficient . . . to support a jury’s finding that defendant’s product was substantially causative of the disease.

Id. (quoting in part Rost v. Ford Motor Co., 151 A.3d 1032, 1044 (Pa. 2016)).

To the great relief of the defense community, the Walsh majority thus cut the Superior Court’s opinion way back.  That opinion, according to the majority’s reading, “neither blessed the indiscriminate use of extrapolation nor . . . may fairly be read to hold that establishing a causal link between cancer and long-term exposure to pesticides is sufficient to support a causation decision regarding exposure to a defendant’s specific product.”  2020 WL 4135151, at *13.  What the majority did hold wasn’t great – “an expert need not rely on studies mirroring the exact facts under consideration,” id. – but that’s not the disaster that the Superior Court’s opinion seemed to presage.

And of course, the three dissenters were not willing even to go that far, rejecting all of the would-be extrapolations as “ipse dixit” ungrounded in any actual evidence.

[B]oth of [plaintiff’s] experts inappropriately extrapolated from “pesticides” as a product class − including numerous pesticides that [plaintiff] never used − to [defendants] specific products, with no analysis of whether the products were chemically, functionally, or toxicologically similar. There is also abundant record evidence confirming that this form of extrapolation lacks general acceptance in the scientific community. . . .  [T]he proffer − before a jury of laypersons − of expert witnesses whose methodologies are replete with ungrounded extrapolations and other analytical gaps, large-scale abstractions, and patent circularity goes far beyond any reasonable conception of appropriate leeway.

Dissenting op, 2020 WL 4139034, at *? (citations omitted).  See Concurring and dissenting op. at *? (final paragraph) (“I join Part II of the Chief Justice’s dissent”).

To us, this is the most important aspect of Walsh.  The product identification requirement comes through unscathed, perhaps even strengthened, as not a single Justice was willing to hold, (as the split Superior Court panel in Walsh actually did) that an expert can assume, from “pesticides cause cancer,” that any particular defendant’s product does so.

Issue Three – Abuse of Discretion

Given the majority’s rulings on the first two questions, issue three became something of an anticlimax.  It’s now an abuse of discretion, in a Frye context, for a trial judge “to make its own bald judgments about which studies relied upon by [an expert] were scientifically acceptable, relevant and/or supportive of [the expert’s] conclusions.”  2020 WL 4135151, at *13.  That was enough – “[i]t is unnecessary for an appellate court to use any ‘magic language’ when ruling that a lower court abused its discretion.”  Id.

So once again, the takeaway for future Frye determinations is don’t go “bald.”  If you’re making a Frye challenge, make sure to build a record replete with your own experts’ reasons why each aspect of the other side’s expert opinion is unreliable junk science.  And if you’re a judge sustaining a Frye challenge, make damn sure that your decision is replete with citations to the record that the parties have supplied.  Ultimately, that’s all that Walsh actually decided.