Sorry, it sounded like you were purposefully soft-peddling. Nader flipped the vote in 2000. No question. Hell, Buchanan probably flipped the vote, even without Nader (although you gotta blame that one on poor ballot design, and not on the third party candidate himself).
I mean, it's a moot point. You can't go back and fix those kinds of things. And you can't unrun a third party campaign. But you're absolutely right that in a close election, a third party candidate can make a difference, because that absolutely did happen in 2000.