It wasn't Jay Paterno, but you're right - it wasn't O'Brien.
It was Tom Bradley, who was the interim coach.
Thanks for pointing that out.
You can tell in the first minute of this clip that it wouldn't be O'Brien's style to act like that:
I think I like the guy.
Meanwhile, for some reason the Steelers flagship stations hired Bradley for their postgame coverage. He's a huge drag.