At the same time, technically, people aren't allowed to touch the talent (I remember a spiel they give before the show starts). I agree that it's probably going to ruin that experience for a lot of fans at this point. But did CM Punk attack the wrong guy, you think? Looking closer at the video, seems like a lot of people touching, shoving, and evening trying to attack Punk. The person in question look like he was shoved into Punk, and then had his arms raised and as he lowered them, he kind of slapped Punk on his head. Punk probably attacked him thinking the fan was trying to get a sucker punch in. I'm not defending what Punk did, but these guys are highly strung during the show and with all those fans and hecklers around, it's hard not to assume that everyone wants to hurt you especially if you're a heel at the moment.
Just read that the fan might sue. First he wasn't going to sue, but I'm sure a bunch of money hungry lawyers, friends, and family have been in his head since the incident. So now he might.