I'm beginning to suspect that the contestants have not witnessed each other's acts. I think they were all just diddling around backstage during each set at the preliminary rounds. Rich mentioned once that he had never seen Dave perform before his showdown with Sean. And the way no one is showing Dat any respect makes me think they haven't seen Dat's act either. So... what's the deal? What's going on? Is the Dat disrespect coming from the fact that they're judging him by what they've seen in the house?
This could have other implications too; if they didn't see each other perform at the auditions, that means the contestants have had the chance to scout some of the other comics (Dave and Cory at the showdowns, Tess at the free show) but some haven't shown what they've got at all. Their cards are still hidden. This could be a serious point.