Courtroom ‘Hot Tub’ Puts Google Trial Experts to Stress Test

Antitrust lawsuits can live and die on the strength of Ph.D. economists. Courts face the crucial task of weeding out which of those expert witnesses can appear before a jury.

Enter the legal “hot tub.”

Federal Judge James Donato in San Francisco this summer turned to the unorthodox hearing format in a case challenging Google’s dominance of the apps sold to Android phone users.

The two-hour-long hot tub pitted competing witnesses, under oath, in a face-to-face debate. It’s a type of back and forth that would never occur during a traditional pre-trial hearing, or even at trial.

Donato, who played ...