I think there is an element of it being a real fight that the people surrounding thought was just dumb, as two mascotts hitting each other is. Its odd for a) apposing teams mascotts to interact, especially if its a rivalry like this, and b) for it to happen while a play is going on in the background. This stuff is usually for breaks in play, as if it was a bit, they would want the crowd to watch, play it up on camera, but a play going on means only a couple people would notice.