He probably should have backed up before the gun was pulled, but instead he charged forward and assaulted someone, thus he is now deceased.
Whatever happens or does not happen to the old man at this point doesn’t matter at all to the one who initiated the assault.
He gave up his life over a parking spot.
Pick the hill you want to die on, as they say.
Not what happened. After the black guy took a step or two forward after knocking him to the ground, before the white guy pulled the gun, the black guy was already stepping back, as if he anticipated the white guy was about to pull a weapon which he did. Watch closely.