Champagne Remark May Cost Lawyer $289 Million Bayer Award

The lawyer most responsible for winning a $289 million verdict against Bayer AG may end up wiping it out.

Brent Wisner was the lead trial attorney who in August convinced a jury that Monsanto Co.’s Roundup weed killer caused his client’s cancer. His compelling arguments and marshaling of evidence resulted in a blockbuster verdict that has spooked investors looking ahead to thousands of similar lawsuits across the U.S. pending against Monsanto, which Bayer acquired in June.

But Wisner’s closing arguments at trial irked the judge handling the case so profoundly that she’s considering tossing the verdict and ordering a ...