It didn’t take long last night, after the news of Jon Stewart’s imminent departure from the Daily Show broke at roughly the same time as news of Brian Williams’s six-month suspension from the NBC Nightly News, for wags on Twitter and elsewhere to suggest that Williams should replace Stewart as host of the satirical news show, his standing as an actual newsman too diminished to ever return to an anchor desk. It’s actually a joke that Stewart himself had cracked, though under happier circumstances, back when Williams appeared on the Daily Show just days before he was to assume the role as NBC anchor. “Why do I get the feeling that you’d be better at my job than I am?” Stewart said, after Williams blindsided him with a joke about Julia Roberts’ birth canal. (It was 2004.)

That segment, and other Williams appearances on the Daily Show over the years, are worth revisiting in the wake of recent events. In them, you see the seeds of the anchor’s demise. That the two men are ending their runs at the same time, one still on top, one very much not, is not simply a newsy coincidence. The rise of Stewart and the fall of Williams are linked.

Much has been made in recent weeks of Williams’ extracurricular activities on the late night circuit, a subject I wrote about for New York back in 2011. For years now, Williams has complemented his work on the nightly news by making appearances on Letterman, 30 Rock, Saturday Night Live. Yesterday, the Times reported that Williams even threw his hat into the ring when NBC began its search to replace Jay Leno on the Tonight Show, an offer NBC executives summarily dismissed, though it’s not as outlandish as it apparently struck the network bosses at the time. Williams is a versatile comic performer and a lightning quick wit. He almost always pulled off whatever comedic challenge he set for himself, or allowed Jimmy Fallon or Tina Fey to set for him.

His appearances with Stewart might be his best comic work. The two men have an obvious affinity: one is a newsman who grew up admiring Carson, the other a stand-up who turned media criticism into a high comic art. Both are Jersey boys made good. The joke running through the anchor’s appearances on the Daily Show was that Williams was the genuine article, a guy who’d reported on wars from the field, while Stewart was a fake anchor who mocked real journalists from the safety of a Manhattan soundstage. In a 2006 appearance, Williams, fresh from reporting on Hezbollah rocket attacks in Israel, described a harrowing ride on an Israeli Blackhawk helicopter, as katyusha rockets whizzed below. “They’re firing real bullets over there,” Williams ribbed Stewart. “Anytime you want to cross over to the other side, baby, travel with me.” In light of recent events, the anecdote raises an eyebrow. In context, it played as Williams puffing himself up mainly to put Stewart down. It was funny stuff.

Of course, Williams was playing with fire each time he strode into Stewart’s ersatz newsroom, running the risk of harming his credibility as an anchor by exposing himself to Daily Show antics (Stewart once asked him if he had been tempted to urinate in Diane Sawyer’s canteen when both anchors were on assignment in Haiti, a suggestion Williams parried with a deadpan, don’t-go-there glare) and by playing this slightly exaggerated version of himself who rejoiced in putting Stewart in his place. Stewart himself warned Williams that he’d better be careful. Back in the 2004 interview, he predicted that Williams the comic would eventually do damage to Williams the newsman. “One day, on NBC Nightly News, you’re going to lose it and say what you really think, and it’s going to be the greatest day of my life.” That’s not exactly how it happened, but it’s not far off. It wasn’t that Williams let the anchor’s mask drop to offer one of the more off-color observations Stewart could occasionally tease out of him; he didn’t make a vagina joke in a “Making a Difference” segment. It was that the raconteur Williams had played on Stewart’s set, and Letterman’s, made a cameo on his newscast, delivering the aggrandized recitation of his helicopter experience in Iraq—the fish story, not the news.

I got to know Williams a bit in the course of profiling him, though not well enough to guess at how, exactly, the truth of his chopper ride became the fiction that has cost him his job. But I think in Williams’ appearances on Stewart you see pressures that might have played a part. Williams recognized early on a shift in the media landscape and, to his credit, didn’t look down his nose at it. He praised the role Stewart played in keeping the real journalists honest. “They hold people to account, for errors and sloppiness,” he told NPR in 2010. “It helps us that he’s out there.” But he also saw that the anchor chair he was inheriting was diminished, in no small part due to the incursions of Stewart and later Colbert, whose comedy became a news source for a younger, more skeptical, not-home-at-6:30pm generation. In the 2004 Daily Show interview, Williams talks a bit wistfully about his belated ascension to the anchor chair, after a decade as Brokaw’s heir apparent. “I feel cheated,” he tells Stewart, when asked about Dan Rather, who had just announced his resignation after flaws in his report on George W. Bush’s National Guard service had been exposed. “I wanted to go head-to-head with those guys.”

In recent days, some commenters have dismissed Williams’s comic moonlighting as the work of a guy who couldn’t stand not to have a camera trained on him, or of a newsman who actually just wanted to be an entertainer. A more charitable view would be that he was an anchor trying to remain relevant in a news environment that, thanks in part to Stewart, was turning him into a dinosaur in a bespoke suit. That’s not to forgive his journalistic sins—far from it. It’s to appreciate the degree to which Stewart, however unwittingly, hastened the demise of the man he shares the media pages with today.

What made watching Williams and Stewart together so much fun was the gusto they both brought to their sparring, with Williams using the tools of comedy to vouch for the gravitas of the news and Stewart using the tools of journalism to deflate the pretensions of the archaic Anchorman. Toward the end of the 2004 interview, when, as usual, the combatants were about to declare their fight a draw, Williams slipped in one last joke—accusing Stewart of harboring a veiled affection for Tucker Carlson—that gave this round to the newsman. “You’re too good at this,” Stewart said, doubled over in laughter. He was right.