The crossroads of medical and legal causation of mesothelioma was on display before the state Supreme Court on Wednesday in a case set to determine whether a plaintiff's expert testimony was based on an impermissible “any exposure” theory of causation.

Attorney Clifford A. Rieders, who represented the plaintiff in Rost v. Ford Motor, told the justices that just because the plaintiff's expert testified that, medically speaking, there is no safe level of exposure to asbestos and a single fiber can potentially cause fatal mesothelioma by damaging a cell's structure, it does not mean that his testimony was substantively based on the “any exposure” theory, which is insufficient to show legal causation.

“You can't conflate the fact that there's a scientific reality” and the expert gave “any exposure” testimony, said Rieders, of Rieders, Travis, Humphrey, Waters & Dohrmann. “That theoretical possibility was not the basis for his case.”