The one that got me was when Edwards mentioned John Kerry when he wasn't supposed to, and then was allowed to shrug it off, and then used his name again with a 'well, I've done it before so I can do it again.' What good are rules if they're not enforced?
Not only did he shrug it off after he did it a few times, he did it with a smarmy smirk on his face, as if to say, "So what? You can't do anything to me."