So when O'Reilly responded Wednesday to Stewart's most recent round of mockery, the Fox News host kept it mostly light, eschewing the temper for which he's so famous.
Stewart used his Comedy Central show to lampoon O'Reilly last week for cutting his vacation short to rail against the media coverage of the events in Ferguson, Mo., the site of unrest and racial tension in the aftermath of the fatal police shooting of unarmed black teen Michael Brown.
Although O'Reilly said Stewart had conveniently omitted comments that were critical of the Ferguson police and sympathetic to Brown, he didn't get too bent out of shape about the comedian's "distortions."
But O'Reilly closed with some advice to Fox viewers that was more than a little rich.
"So, here is the Factor tip of the day: When you hear something on a partisan-driven program, do not believe it," O'Reilly told his audience. "And that includes the 'net. Don't believe this stuff. Distortions are how some people make a living. Stewart's going for the laugh. He doesn't really care if it's true or not."