Chris Stirewalt joined MSNBC's All In last night and and was forced to admit that Fox News lies to their viewers constantly.

Hayes did not let him off the hook.

Stirewalt was laid off from Fox after a contentious post-election season. He was instrumental in analyzing vote counts and calling Arizona for Biden on election night at Fox. That was his job. Fox News viewers were not pleased. After he was banned from appearing on air in November, Stirewalt was laid off earlier this month.

Stirewalt blamed his tumultuous experience on "the pitfalls of a 24-hour news cycle" in an LA Times op-ed:

Having worked in cable news for more than a decade after a wonderfully misspent youth in newspapers, I can tell you the result: a nation of news consumers both overfed and malnourished. Americans gorge themselves daily on empty informational calories, indulging their sugar fixes of self-affirming half-truths and even outright lies.

Chris Hayes indulged his point, but then shifted to the root of the matter. Fox News lies to its viewers on a regular basis and that's a horrendous thing for the country at large.

Hayes said, "The deeper problem is that your network, the president (Trump), was feeding people substantive lies. Incredibly important, material lies about the world."

He continued, "Not like ‘The Dems are bad,’ or we don’t like them, they were lying, they were giving them mistruths about the state of the world. That’s a substantive problem with what was being pumped out, not a formal question of the 24-hour news cycle.”

Stirewalt grudgingly replied, “Well, I hear you."

The former Fox digital political director then defended his actions on the network.

This caused Hayes to raise his eyebrows, (I don't think I can do that) which caused Stirewalt to comment on the visual.

“You raise whatever eyebrow you want to raise, I wasn’t pumping out mistruths,” Stirewalt said -- and for the most part, he is correct. He wasn't a firebreather for Donald Trump.

Hayes replied, “No, my eyebrow is that the network you worked for was.”

The MSNBC host concurred that there are problems inherent about their industry that Stirewalt said were correct, but he went back to the crux of the matter.

"I don't lie to them. Because it is important to me to not to lie to them," Hayes said.

Stirewalt agreed.

Hayes continued, "There are people on the network you worked for that are lying to people. And it’s really bad for the country. I don’t know any other way to say it. But that’s just where we are.”

“Lying to people is a bad thing to do,” Stirewalt admitted and again said he wasn't one of the many Fox News liars.

Hayes was glad that he had been liberated by the powers at Fox to tell the truth, but hey, now he's not working there anymore. hmm.

I debated Stirewalt years ago on MSNBC when he was still working for the Washington Examiner and he isn't a liar like many of their hosts.

But because of the actions by his former network, telling the truth now gets you fired.

Frances Langum contributed to this post.