While it's understandable that it happens a lot, people lie, and leave, and should be given second chances, they don't normally do it constantly for their entire career. I can't think of one other prominent figure in athletics who has done it with the consistency that Petrino has. He lied and left in his first stint at Louisville, he lied and left in week 13 with the Failcons, he lied to his wife and kids and finally caught some consequences at Arkansas, but it didn't stop him from lying at the same pace and leaving at WKU. There's no evidence that this guy is anything other than a liar, or that he did any of those things for redeeming reasons. This is a guy who has had his second chance, and his third, and his fourth, and so on.
Joe messed up once. Sure, it was in a very big way, but he didn't establish himself as a person without any control over his issues, as Petrino has. By all indications, Joe deserves a second chance, as did Petrino. They both got it, but that's where the similarities end. I'm not trying to bash Petrino, but to say that he deserves a second chance when he's on his sixth or seventh chance is wrong, as is to conflate his character with Joe's.
I'll enjoy watching his tenure at Louisville as much as the next guy, and I don't begrudge him his job. I'm just stating my opinion: Petrino is a risky hire for Louisville in a lot of ways. They are gambling that the football good will outweigh whatever bad, or that they can contain or control it somehow. I don't believe for a second that Jurich thinks Petrino is a changed man. Jurich is a pretty smart guy, and he's got as much dirt on the man as I do, and certainly then some. Jurich and Petrino just have one thing in common that has brought them back together: winning football games.