By any normal standard, this should have been the end of the case. After all, what was left to litigate? But it wasn’t the end — not even close. In 2018, after Judge Kaplan’s judgment had finally been affirmed, the company brought another case against Mr. Donziger. Among other things, it wanted him to turn over his computer and other electronic devices. Judge Kaplan agreed. But Mr. Donziger refused to comply, saying it would give the oil company “backdoor access to confidential attorney-client communications.”

In 2019, the judge took the extraordinary measure of bringing in a private law firm to prosecute Mr. Donziger for criminal contempt of court. This case was presided over by another district court judge, Loretta A. Preska, who quickly ordered that he be placed under house arrest and wear an electronic ankle monitor. After a short trial earlier this year, she found Mr. Donziger guilty, and sentenced him to the six months he is now serving. He was also disbarred.

Along the way, something surprising has happened: Outside the courtroom, it was as if the ghostwritten report and the alleged bribe of the Ecuadorean judge had never happened. Mr. Donziger’s victory in Ecuador was praised as legitimate, and he was widely viewed by progressives as an environmental hero. Sting, the musician, helped raise money for his defense. Greta Thunberg offered her support. Representative Alexandria Ocasio-Cortez and several of her Democratic colleagues sent a letter to Attorney General Merrick Garland, asking him to review the case. The Harvard Law professor Charles Nesson rallied to his cause. Campaigns have been started to #FREEDONZIGER. A group of experts from the United Nations said in a report that his pretrial detention was “arbitrary” and therefore illegal. And on, and on. To them, this was a classic example of a fossil fuel company using its might to punish someone brave enough to stand up to it.

This phenomenon of seeing controversial figures as black or white — saint or sinner, hero or villain — is one of the plagues of our polarized age. It has become nearly impossible for people to acknowledge that sometimes their heroes can do something wrong, and their foes can get something right. Donald Trump is the most obvious example of this, but you see it all the time in politics, and in business as well. Are C.E.O.s rapacious greed-heads, or are they stewards of capitalism? Are oil companies supplying the fuel that the world needs to function, or are they “outlaws,” as the environmental activist Bill McKibbon calls them? Too many people are unwilling to hold both ideas in their heads at once.

This failing is especially glaring in the Donziger case. If he had played by the rules in litigating the case in Ecuador, he might have come away with a judgment that a U.S. court would have upheld. Chevron would have had to pay billions to his impoverished clients. To put it another way, by using the tactics he did, Mr. Donziger did his clients an enormous disservice. That his allies refuse to see this suggests their hatred of Big Oil has blinded them to some of Mr. Donziger’s inconvenient actions.

But then there is Chevron. Companies are supposed to make rational risk and reward calculations. The company’s push to prevent the Ecuadorean judgment from going into effect was rational, and showing that Mr. Donziger had violated the rules was an appropriate way to do that. But punishing Mr. Donziger beyond that may ultimately have been a mistake. He has been turned into an environmental martyr, which is the last thing Chevron should want. He’s no longer the lawyer who broke the rules to win a case. Instead, he’s the lawyer who stood up to Big Oil.