For sure some judicious marksmanship.Hmm maybe he feared the guy was going to come at him again.
Why give him the chance.
All falls into stupid games, thankful he was focused enough to plug the right guy in a white T shirt.
Personally i think this looks like some hood rat shit, while I know these encounters happen, the cool walk to the exit throws off some serious street vibes. Shooter knew that guy was going to die the moment he hit the floor, he just planned his escape first.