Doctors thought he would be dead before he could testify, but Dewayne Lee Johnson had a story to tell and lived to do so.

One morning on the job as a school groundskeeper in California, his sprayer broke, drenching him in what he called “the juice”: the weedkiller Roundup. Johnson later was diagnosed with non-Hodgkin’s lymphoma, a form of cancer, and subsequently sued Monsanto Co. It was the Roundup that had made him sick, he alleged.

Johnson’s lawsuit is over now; he received $20.5 million after Bayer appealed a jury award of $289 million. But his case reverberated anew in a San Francisco courtroom last week, on May 19, as attorneys for Bayer AG, which in 2018 bought Monsanto and its Roundup line of herbicides, asked a U.S. District Court judge to approve a proposed settlement of $2 billion for all such suits in the future. As the first person to take Monsanto to trial, alleging the company hid Roundup’s cancer risks – and the first to win such a case – Johnson helped pave the way for Roundup litigation by multiple others.

Also reverberating at that hearing was the case of Edwin Hardeman, who, on Christmas Day 2015, found a swollen lymph node in his neck that turned out to be non-Hodgkin’s lymphoma and subsequently sued Monsanto. Five days before, on May 14, the U.S. Court of Appeals in San Francisco refused to overturn a jury’s $25 million judgment and trial verdict in Hardeman’s favor, a decision some expect will drive more claims beyond the thousands Bayer is trying to resolve in a separate $11 billion settlement.

Hardeman’s case, the only one to go to trial in federal court, was the second of three Roundup trials Bayer lost in 2018 and 2019, with average awards of almost $50 million per plaintiff, and the prospect of untold others is behind Bayer’s quest for a controversial $2 billion class action settlement that would cap the company’s legal exposure.

Though Bayer maintains Roundup is safe, the International Agency for Research on Cancer classifies the weedkiller as a probable human carcinogen. The groundbreaking verdict in Johnson’s case said Monsanto “acted with malice” and knew or should have known its chemicals were dangerous.

Detractors of Bayer’s proposed $2 billion settlement, including many law firms, say it would be of little help to cancer patients. The proposed class-action settlement, which is separate from the $11 billion settlement for already-filed lawsuits, would apply to people exposed to Roundup as of February 3, 2021, but who have not yet sued Monsanto or retained a lawyer to do so.

Bayer’s proposed $2 billion settlement would set a dangerous precedent, said Colleen Blinkoff, a partner in the Buffalo law firm Doran & Murphy. “I don’t think the average person understands how much this could impact everyone by way of setting a precedent of a corporation being able to limit exposure for liability into the future,” Blinkoff said. “This is quite controversial, because usually you can’t set up a fund for future claims without declaring bankruptcy; a company typically can’t limit their future exposure for claimants who haven’t been injured yet and are therefore not able to object to the sufficiency of the settlement.”

The strange marriage of Bayer and Monsanto began in 2018, when the former, a company known for its aspirin, shelled out $63 billion for the latter, known for its weedkillers. Roundup figured prominently into Bayer’s calculus to buy Monsanto, but the weedkiller has since proved something of a headache for its new owner, whose investment in Monsanto not only placed Bayer in the crosshairs of thousands of lawsuits but also at one point hurt its stock.

Those believed to be at risk because they use or used Roundup include farmers, groundskeepers, landowners, and railroad workers, who spray the herbicide from special cars to keep railbeds free of weeds so engineers can see and tracks stay structurally sound. The judge considering Bayer’s proposal for a $2 billion settlement has suggested a warning label on Roundup.

“The fact that the companies are continuing to sell a product that, at the very least, have huge questions about their safety, is what is driving these cases,” Blinkoff says.