Much of the admissibility action occurs under Daubert, but it’s good to remember that Frye still holds sway in several important states. In that regard, the Pennsylvania Supreme Court’s decision in Betz v. Pneumo Abex, LLC, 44 A.3d 27 (Pa. 2012), is a reminder that Frye, can, when properly applied, approach the rigor of a good Daubert ruling.

The expert testimony in Betz involved the infamous “every fiber” opinion, under which every single exposure to asbestos—no matter the circumstances—is deemed a substantial contributing factor to disease causation. Although a few courts tolerate that opinion as a matter of practice, a number of judges who have faced the issue head-on have rejected it as utterly devoid of scientific support and, frankly, at odds with the implicit notion in substantial factor causation that some factors are not substantial.

What is significant about Betz joining that list (earlier decisions had forecast the result as to the “every fiber” opinion) is the searching application of Frye the Court endorsed. The trial judge ably walked through the gaps in the expert’s reasoning and the limits of the bases for his opinion, refusing to defer to an expert’s vague claims to be practicing a scientific methodology. As under Daubert, that kind of open-eyed, fulsome review will knock out junk science. Betz reminds us that, whatever its flaws, at 89 years and counting, Frye can still punch.