By the "victim" refusing medical attention, belligerent to LEO's, and asking neighbor to not call police, I wouldn't use this example for a 2nd Amendment argument. Sounds like there's a LOT we don't know about.
Yeah, if he had just allowed medical treatment of himself and called the cops on his own this would've been a lot better....in addition to making sure his line of fire was clear, which can be downright impossible in an apartment.