Plaintiffs’ lawyers in Monsanto weedkiller trial face tough hurdles

A San Francisco County jury found that Monsanto Co.'s signature weed killer caused a dying man's cancer last year, but the consolidated cases that open in federal court Monday will most likely have a much steeper hill to climb, legal experts say.

Attorneys representing thousands of people diagnosed with Non-Hodgkin lymphoma face formidable hurdles on multiple fronts, including the trial being split into two phases and the exclusion of critical pieces of evidence that were allowed in the state court case.

"It's going to be hard [to prove causation], because what we're talking about is a plausible biological link," said Stanford Law School professor David M. Studdert. "It's not a home run for the plaintiffs in this case."

The bifurcated trial will only consider issues of causation in the first phase. If the nine-person jury, which is composed of seven women and two men, finds the agrochemical company liable, it will then hear allegations of misconduct and whether additional damages are warranted.

The first of the test cases start before U.S. District Judge Vince Chhabria of San Francisco.

Edwin Hardeman is alleging exposure to Roundup was a substantial contributing factor in his development of Non-Hodgkin lymphoma, which he was diagnosed with in 2015. In re Roundup Products Liability Litigation, 16-MD02741 (N.D. Cal., filed Oct. 4, 2016).

The defense argued splitting the trial would avoid undue delay, while plaintiffs' attorneys contended the process is "unheard of" in modern multi-district litigation.

"It is simply never done, and for good reason," wrote plaintiffs' attorney R. Brent Wisner.

While it is reasonable the court does not want evidence of misconduct influencing the jury's judgment on the scientific questions, the pretrial rulings, namely the bifurcation, were largely favorable for the company, now owned by Bayer AG, according to UC Hastings College of Law Professor David Levine.

Studdert also said that the splitting of the trial should be of particular concern for plaintiffs' attorneys because even if they emerge victorious in this case, they have to prove specific causation in all the other cases if they go to trial.

"There are two mountains to climb," he said.

Unlike the state court case, much of the evidence concerning the International Agency for Research on Cancer's conclusion that glyphosate is a probable human carcinogen will be excluded, as will evidence of the Environmental Protection Agency's decision to classify glyphosate as "not likely to be carcinogenic to humans."

Chhabria has previously referred to the opinions of many of the plaintiffs' expert witnesses as "shaky," in his order on summary judgment.

While the fact of both agencies' classifications will be admissible at both phases, expert witnesses will not be allowed to discuss the matter "to avoid wasting time or misleading the jury, as the primary inquiry is what the scientific studies show, not what [they] concluded they show," Chhabria wrote in his rulings on motions in limine.

The judge emphasized the experts "must limit their scientific testimony to their own independent conclusion."

In another blow to plaintiffs' attorneys, Chhabria also prohibited references to Monsanto's ghostwriting of studies in the first phase of the trial.

Levine said the judge most likely thought the probative value of testimony concerning the company's efforts to influence the science would be outweighed by its prejudicial value, but that he could have balanced the dispute better by allowing limited testimony on the issue.

He added that much of this case could come down to who tells a more compelling narrative, which plaintiffs' attorneys are disadvantaged by because allegations of misconduct are not allowed in the first phase of the trial.

References to Monsanto's marketing materials, other litigation and certain studies and internal records were also excluded.

"No matter what happens here, it's not the end of the story," Levine said. "We're still at the very beginning of this whole saga."