And don't get me wrong, I've done it before too, even though I try not to do it. It's just hard not to.
When I see it I can't help to wonder if it's the "Sup" bro-nod.
Or if it's the silent acknowledgement like when the waiters nod at Tyler Durden in Fight Club.
Or if it's like shaking hands and saying "good game" after a sporting event.
But it's none of that. A guy just killed someone. And then he nods at him. And then the guy he kills nods back! What is it? Is it professional courtesy? Is it being a douche? No idea...
Imagine seeing a guy jump some other guy in a bar, completely wreck him and then nod at him while he's broken and bloody on the ground... And then getting a nod back! It's insanity. Haha.