It would have been quite the interview had it aired. As it is, a testy exchange between Tucker Carlson of Fox News and Dutch historian Rutger Bregman is making headlines nonetheless—because Bregman recorded it himself and leaked it to the media outlet Now This.

How testy? At one point, Carlson says, "Why don't you go f--- yourself, you tiny brain. ... You're a moron. I tried to give you a hearing but you were too f---ing annoying." The details:

  • Who is Bregman? The historian first came to the world's attention last month in an appearance at the Davos economic summit, reports the Guardian.

Among other things, he railed against the hypocrisy of the world's elites traveling first class to the summit to hear about environmental dangers.

  • A viral rant: This clip from Davos went viral.

Bregman complains that nobody at the summit is talking about taxes and the ways rich people avoid paying them: "It feels like I'm at a firefighters' conference and no one's allowed to speak about water."

  • Friendly invite: Carlson invited Bregman on as a guest to his show, ostensibly so they could join together in railing against global elites, writes Erik Wemple of the Washington Post.

And indeed, the interview begins with Carlson lavishing praise on Bregman for his Davos comments. But Bregman unexpectedly turns the tables. (Watch it here. Vox has the transcript of the early exchange.)

  • On the attack: Bregman goes after Fox and Carlson himself: "What the Murdochs basically want you to do is to scapegoat immigrants instead of talking about tax avoidance." He also says Carlson is "a millionaire funded by billionaires" and "not part of the solution" but "part of the problem, actually."
  • Pulling the plug: An angry Carlson ends the interview after a slew of insults—"and I hope this gets picked up," he says at one point—and Bregman called him on it the next day.

"Why didn't you air the interview with me last night?" he tweeted on Feb. 12. "Couldn't handle the criticism?"

  • Carlson responds: Carlson himself talked about the interview on his show Wednesday, reports USA Today.

He acknowledged that his comments were "rude," but he said they were also "entirely accurate," and "genuinely heartfelt." As for Bregman's accusations: "Whatever my faults or those of this channel, nobody in management has ever told us what positions to take on the air," he said.

"Never. Not one time."

  • Fox explains: The show's executive producer, Justin Wells, explained why the interview didn't air. "Tucker is someone who appreciates many points of view," Wells said, per the Hill.

"Sadly, the guest turned an opportunity to have a substantive, informative discussion into an obviously calculated personal insult campaign."

  • 'A trap': Carlson gets a sympathetic ear from progressive Cenk Uygur of the Young Turks.

He notes that Carlson clearly wanted to talk about tax avoidance, but Bregman wouldn't engage. “It clearly was a trap and he fell into it," says Uygur, per Mediaite. "Let’s just keep it real, that’s what happened.”

  • Not surprising? "If Carlson had actually read Bregman's book Utopia for Realists, or read his interview with Vox where he condemns right-wing anti-immigrant populists ... none of this would be surprising," writes Dylan Matthews at Vox.

Given that Carlson has gotten into hot water for saying immigrants make America "dirtier," this interview "was bound to end in a fight, one for which Carlson apparently wasn't prepared."

This article originally appeared on Newser: Heated, Unaired Interview With Tucker Carlson Leaks