Doesn't matter what the argument was about, parking space or the price of bread, who cares.
I don't think this is a "stand your ground" case because the shooter didn't have the choice to leave or stand his ground.
I think this is legal self defense. The Sheriff said there was one shot fired, I disagree, I'm seeing at least two shots, the last one connected. The dead guy had not started backing away yet when the first round was fired, he was pulling his pants up and leaning in.
It's definitely a close one to call though. Without the gun, the way I see it playing out is the older guy crabwalking backwards across the parking lot on his *** while the younger guy kicks him multiple times. With that being the alternate outcome, I think this is a good shot.