Not his own TV career, of course, but Glenn Beck's. In a Rolling Stone profile from 2007, Olbermann had a lot to say about Beck:
A wolf in sheep’s clothing. The very dangerously bigoted guy who is selling himself as a pragmatic philosopher. I don’t think he sees his own bigotry. There’s something about him that suggests that, one night, he’ll say something that will cost him his career in television.
I guess Olbermann had the right idea, just the wrong host. In retrospect, this is just more evidence that if you take everything Olbermann says and then flip it 180 degrees, you find the truth.