If, in fact, Rudolph was trying to rip the guy's helmet off- looks like he was- then Rudolph deserves to get his helmet ripped off. And he did.
It should've ended there. An eye for an eye.
If you think, and this goes for anyone who thinks alike, that swinging the helmet isn't criminal; you need some deep self-introspection, a worthy psychologist, and a low dosage anti-psychotic.
Just ask yourself if you could do that to someone on the street or have someone do it to you. No cops? No criminal activity? Nothing to see here?