For this to be a legal shooting we would have to believe the old man REASONABLY believed his life was in danger at the moment he shot. I do not.
Here is where I take exception. No matter what I am saying, if I am merely saying something and someone comes up and slams me to the ground, I might shoot if I had a gun. Anyone so mentally unstable as to use (any) excuse for the first point of contact to be assault, has to be assumed an immediate and persisting threat.
What would make them less of a threat, is if I were able to get up and have a fair defense, but odds are that right after someone attacks you like this, their only hesitation in pummeling you further is if you don't get up, but if you don't get up then the last thing you may ever see is the kick to your head. Taking a step or two backwards is not at all a retreat, is what anyone might do right after they slam someone to the ground, before continuing to assault them. Clearly the man did not and was not going to retreat because his car was right there.
This is the unfortunate state of society today. While I *
might* shoot the guy in the same situation, what I'd have done differently is not be in that situation in the first place, so yeah the shooter is guilty of manslaughter. I don't buy being guilty of murder because he didn't pull the gun out until after assaulted. You can't really claim that words justify (instigate) violence, without simultaneously throwing away our right to free speech, a right that is far more valuable than any one life.