Seems to be a bit of an overreaction on both accounts. I have a buddy who was in a very similar circumstance - and on a Friday, and he ended up in jail for the entire weekend until a judge would see him Monday morning. If someone took a swing at me I might have the same reaction but I wouldn't have patted him on the shoulder in the first place. There are so many "what-if" here that it hopefully would make you reconsider your actions if you could do them over again - like if when he dropped he hit his head and cracked it open or he fell on to a bottle - things that could get you serious prison time for something as seemingly innocent as punch.

Chances are that if you got arrested for it that not much would come of it but it all would depend on the judge.