It wasn't a lie. It was a truth he was denying to himself up until that point. She was manipulating him but he opened himself up to it because he was being manipulative himself. So she did use him but it wouldn't have happened if he wasn't using her himself. So his crime wasn't being wrong about her using him, it was…

I'm in no way a Dane Cook fan, but no person who writes for that hack Jimmy Fallon should bash someone else for being an unfunny hack. It's like Stalin bashing Hitler for human rights abuses. No credibility.