fuck him up

True, and the sad thing is the law will probably side in the retard's favor so reporting it will do nothing. Your best bet is to take revenge on him by planning a well thought out assault on him. Make sure nobody sees it, beat him senseless and deny everything, nobody will believe a retard anyhow.

How exactly did you react in the first place when it happened?

well dude i dont think he should have hit the dog but keep in mind that if the dog had been on the leash with the leash in your hand he could not have approched the guy in the first place, as it has been said many times in this thread many many people are terrified of dogs even puppies so to prevent further injury keep the dogs leash on your wrist or tied to something so he cant approch anyone that doesnt want him near, with all that said i hope the dog is ok

I'd say leave him alone.

Knock him the fuck out anyway. :pimp

Thats what I would do. Why held back cuz he's insane? Fuck that shit.