The former "Access Hollywood" and "Today" anchor told the late-night host he had grown frustrated and upset after hearing that President Donald Trump had recently made statements disavowing that it was his voice heard by millions who viewed a 2005 outtake of an "Access Hollywood" tape on which Trump claims to harass women sexually.
He joined the CBS late-night program for an interview after the tape came back into the news following a New York Times report that said Trump allegedly told a senator that the tape was fake - despite apologizing for its contents after it was released past year.
"You worked on the Today Show", Colbert told his guest, who was making his first late-night appearance in over a year.
"If you don't mind, I'm going to roll the tape", Colbert said at the beginning of their conversation. You were there. I was there. That is your voice. "But it was right after the debate and I think the tape made it in time for the debate, so I didn't get that".
That was the tape that caused an uproar - but obviously did not derail - Trump's 2016 presidential campaign when the candidate was heard boasting to Bush that as a celebrity, he can "do anything" with women, including "grab them by the pussy".
"I said, 20 women don't get together and say, 'You know what would be really fun, let's take down a powerful guy together.' No, they don't", Bush said. "We've got powerful people being held accountable now and sometimes there are anonymous sources", Bush said in an interview Monday on the "The Late Show with Stephen Colbert" on CBS.
"If I had thought there was a man detailing a sexual assault strategy to me, I would have called the Federal Bureau of Investigation, not just my executive producer", Bush stated. Haha.' No, they don't. "I think it was very hot emotionally. A lot of people were not comfortable with the man who was close to winning the election and a lot of things happened quickly", Bush, 46, said. On the day Trump was inaugurated, "I was checking in to a soul-searching retreat in California", Bush said. "But my boss, said publicly months later, 'I think we may have moved a little quickly".
"It was 2005, and his ratings were through the roof and he was the big star of NBC".
"He was just regaling the seven guys on there and doing his bit", he said. "If I had thought there was a man detailing a sexual assault strategy to me, I would have called the Federal Bureau of Investigation, not just reported it to my executive producer", he said. "I said, 'I appreciated it, ' and accepted it and thanked him".
And it appears that some of the higher ups at NBC regret Billy's firing - and Matt Lauer even defended him.
When it comes to the national conversation of victims reporting sexual abuse and harrasment, he said, "Women must be believed". "I'm anxious that the dialogue isn't going to be around, because we get on to the next thing, we get on to our phones, the next outrage comes".
"It's really the dumbest thing he could have done", Colbert said, adding wryly -"He's a dumb, dumb person".