>>either had a huge ego or sense of self-importance that got the best of him
That might also be said of the victim.
He might be alive if he'd just apologized and shut up.

A few disastrous episodes that I saw as a kid in the military taught me that arguing in cases like this is dangerous and being "in the right" doesn't mean much if you're dead or maimed.
You can't know what might be going on in the head of that other person.
You might be pouring gasoline onto a fire with each word.

My kids and grandkids have heard ad nauseum from me that if an argument with a stranger becomes even slightly heated, APOLOGIZE AND GET THE HELL OUT OF THERE.