On April 30, the U.S. Environmental Protection Agency declared glyphosate, the active ingredient in the widely used weedkiller Roundup, to be safe. Less than two weeks later, a California jury ordered Bayer AG to pay $2 billion to a couple who blamed their non-Hodgkin's lymphoma on Roundup.
How can jurors ignore the nation’s primary regulator, as well as virtually every other national regulatory agency on earth, and decide Roundup caused a relatively common cancer of the bloodstream that even plaintiff medical experts said usually has no identifiable cause?
The answer is juries do it all the time. Dow Chemical paid billions of dollars to end litigation over silicone breast implants manufactured by its Dow Corning joint venture even though the plaintiffs’ scientific theory that silicone was a slow-acting poison was ultimately shown to be bunk.
Other examples include the nausea drug Bendectin, falsely accused of causing birth defects, and asbestos lawsuits over automotive brake pads, which large-scale epidemiological studies have shown do not increase the risk of cancer.
The main tools plaintiff lawyers can use to win these large verdicts are scientific uncertainty and incriminating documents, which when combined can convince jurors to switch the burden of proof from the plaintiff to the defendant.
Instead of deciding whether the defendant’s product caused the plaintiff’s injury, the jury can end up deciding whether the defendant has proven its products are safe - sometimes a nearly impossible burden. Emails and other evidence suggesting the defendant tried to influence scientists and regulators or hide information from consumers help convince jurors they are punishing bad behavior instead of deciding a scientific question, said David Bernstein, a professor at the Antonin Scalia Law School and expert on toxic tort litigation.
“Really in these cases the plaintiff doesn’t have the evidence,” Bernstein said. But if you shift the burden of proof, “jurors say, `We think the defendant acted badly, and unless they can prove it definitely didn’t cause disease, we’re going to find for the plaintiff.'"
All those tactics were on full display in the latest Roundup trial, the third so far that Bayer has lost. Attorney Brent Wisner used expert witnesses and carefully selected emails and other documents to convince jurors that Monsanto employees improperly ghostwrote scientific studies and pushed the EPA to declare its products safe.
Expert witnesses cast doubt upon studies of tens of thousands of farmers, who are exposed to far more Roundup than the plaintiffs, finding no higher rates of non-Hodgkin's lymphoma. They urged jurors instead to look at a smattering of laboratory studies suggesting glyphosate had increased the cancer risk in animals.
Jurors also apparently downplayed the substantial preexisting risk factors both plaintiffs had for contracting non-Hodgkin's lymphoma. Alva Pilliod had three types of skin cancer and ulcerative colitis and his wife Alberta had Hashimoto’s disease, an autoimmune disorder that some studies have associated with an increased risk of lymphoma. Both were over 50 when they were diagnosed and the risk of lymphoma increases substantially with age.
Bayer maintains Roundup is safe, and said it will appeal this latest ruling as well as the two previous ones. The EPA’s findings announced April 30 were based on more than 800 studies that failed to find a connection between glyophsate and cancer, Bayer said, while the plaintiffs used “cherry-picked findings from a fraction of the studies available” and failed to adjust some study findings for exposures to other pesticides.
“The verdict in this trial has no impact on future cases and trials, as each one has its own factual and legal circumstances,” Bayer said. “Also, this litigation will take some time before it concludes as no case has been subject to appellate review where key legal rulings in the trials will be assessed.”
Bernstein has written extensively about how the U.S. court system consistently delivers jury verdicts that seem to be at odds with the scientific evidence. One problem is civil trial procedure hasn’t changed much since the 1800s, when trials were brief and evidence was mostly in the form of eyewitness testimony.
Now trials go on for weeks, with scientific evidence presented in random order. Jurors only receive their jury instructions, on how to decide the facts, at the end of the trial, meaning they are ill-equipped to assess expert testimony in the light of the precise factual findings they are being asked to make, Bernstein said.
Psychological studies have shown up to 90% of jurors have made up their minds on the defendant’s liability long before they begin deliberations, Bernstein said. And that predilection plays to the advantage of plaintiffs if their lawyers can inject enough uncertainty into the science, a reversal of the now-famous efforts by the tobacco industry to raise doubt about whether cigarette smoking caused cancer.
Expert witnesses are crucial to these cases. Experts for the Pilliods included Chabi Nabhan, until February the chief medical officer at Cardinal Health in Chicago, who told jurors he was convinced Roundup caused non-Hodgkin's lymphoma in both plaintiffs despite their other risk factors.
Under cross examination, defense attorney Tarek Ismail probed Nabham’s reasoning process, including why he eliminated age, sex and autoimmune disorders as potential causes but left in Roundup. Nabhan cited weak epidemiological evidence as one reason, yet he downplayed the numerous epidemiological studies that also undermine the theory Roundup causes cancer. Jurors apparently believed Nabhan.
Judges can strike experts whose opinions aren’t backed by solid scientific method but in many states, including California, the rules on excluding testimony are loose. Federal judges must adhere to much stricter rules based on a trio of Supreme Court decisions prohibiting questionable scientific testimony but even in federal court, judges are often inclined to let the experts speak and leave jurors to decide which ones are credible.
If judges exclude plaintiff experts, however, frequently the case collapses as there is no scientific evidence left.
Judges also have the authority to pick their own experts to explain complex scientific evidence to lay jurors, but rarely use it, Bernstein said. Plaintiff lawyers hate the idea of losing control and defense lawyers aren’t enthusiastic either, he said.
For defense lawyers, “it’s OK to lose, but It’s not OK to lose in an unusual way,” he said.
The result is jurors hear experts from both sides who tend to represent the far edges of scientific consensus. Often they earn $1 million or more a year at standard rates of $500 an hour and can be deft at deflecting questions about their methodology under cross-examination. Presented with conflicting opinions from highly paid witnesses on both sides, jurors may just default to the easier question of whether the defendant behaved badly.