There is nothing to suggest Petrino is a devious guy or purposely sabotaged Pittman's job. Pittman lost his job because he was a bad head coach. If he was not such a likable guy, he probably would have been gone a couple of years ago.He seems like a devious enough kind of dude to do something like that.
Regarding Petrino, he made a mistake almost 20 years ago and he has paid for it. He has done nothing like that since. It's time for people to let it go.