You consider trying to poke someone's eyes a mistake? I would call it a mistake if he didn't know what he was doing was wrong. A mistake would have been helmet to helmet contact while sacking a quarterback, not doing something like poking someone's eyes which has no bearing on making an aggressive move for the ball in football. He is apologizing because he got caught.
Say you're at work and decide to try to poke someone's eyes repeatedly ON PURPOSE. I really doubt all you have to do is say sorry and take a day off afterwords.