Those defending the ref..... watch other games, you will see much worse than what X did and it is not penalized 99.5% of the time.
Heck, just watch yesterday, I think it was Oklahoma's last TD. Their QB ran about 50 yards for a TD. The last 10 yards he was holding his arm straight up over his head, waving his arm with the ball in his hands and looking around. No flag. I don't think the ref even came over to him in the end zone to tell him to calm down, which you do see a lot. He "celebrated" or "taunted" or anything you want to call it, much more than what X did.
As some have noted, this had to be a ref that was just hell-bent on making a call against ISU, we will never know why.