And by "you all" I realize I'm talking about ten guys on a internet forum. Most people at the game won't even think about it.

He's wearing Aggie gear because that's his school. Worst case scenario is this: BYU and Utah State are rivals, and this is his way of cheering against his rival, which is perfectly normal in college football. You all have an entire category for trashing your rival. Actually going to the game seems more fun than just trash talk on the web. He's not a jerk or an idiot.