When the president sat down for an interview with The New York Times, he all but begged his own attorney general to resign. Instead, his legal team’s own spokesman called it quits.

Mark Corallo, who had spent months defending President Donald Trump as spokesperson for his personal legal team—headed by longtime Trump attorney Marc Kasowitz—confirmed to The Daily Beast on Friday morning that he resigned. He didn’t provide any detail on his reasons.

But people who have known Corallo for years said the president’s New York Times interview, where he questioned Attorney General Jeff Sessions’ integrity, meant he had no choice but to leave.

“To people who know him, his choice to leave was unavoidable on a moral and professional level,” said a longtime friend of Corallo’s.

“Anyone with Mark’s professional capabilities would have seen The New York Times interview was a debilitating P.R. calamity,” the friend added. “To direct broadsides on Mueller and the A.G. is going to be impossible from which to recover, and Corallo certainly would have known that. It makes total sense that he got out of dodge. He’s always had tremendous political instincts.”

Another person who has known Corallo professionally for years said he couldn’t keep working on the president’s defense team after that interview.

“It’s the most unprofessional thing Trump has done to date, getting in Sessions’ ass and getting in Mueller’s ass,” the longtime colleague said. “You can’t do that. There’s no attorney in the world that’s going to want a client that’s doing that. First of all, it’s impetuous. But in addition to that, it makes the legal defense team, including Corallo, look really bad, because a lawyer would never advise their client to do that. And if you don’t make a stand on that, then tacitly, you agree with it.”

And Corallo clearly didn’t. From the moment Sessions was nominated attorney general, he was an unequivocal supporter of the Alabaman senator. And he wasn’t at all shy about ripping into the president’s potential adversaries.

And when Sessions recused himself from the Russia probe after news broke that he didn’t tell the Senate about meetings he had with the Russian ambassador, Corallo said it was “a non-story.”

“Since when is it improper for a sitting U.S. senator to have contact with a foreign diplomat?” Corallo told The Daily Beast at the time. “This is more evidence that the Democrats, and career bureaucrats in the intelligence community (pardon my redundancy) who oppose President Trump are desperate.”

Corallo, who was the spokesman for John Ashcroft when he was attorney general, defended Sessions through thick and thin.

Corallo’s resignation comes at a time when the attorney general is facing more fire than ever. The Washington Post reported Friday evening that intelligence intercepts show Sessions discussed campaign issues with the Russian ambassador, despite saying under oath that he never did so. The story will kick off another round of calls for his resignation from Democrats—and at a time when the president is wholly uninterested in defending him.

For some Republicans, Corallo’s resignation means Trump’s evolution into his own worst enemy is now complete. Ed Rogers, a well-wired Alabama Republican who’s chairman of the BGR Group lobbying firm, told The Daily Beast that when he read the president’s New York Times interview, his first fear was that it would result in good people leaving the administration—a concern he detailed in an item for The Washington Post. Corallo, he added, was a “seasoned professional,” and he said he wished he hadn’t resigned.

But, Rogers continued, only one person is responsible for this mess: Trump himself.

“Trump brings discord where it’s hard to do,” Rogers said.