He unholstered his weapon only after being verbally threatened, but he didn't point it. He then reholstered after assessing that it wasn't needed, only to be physically assaulted. If anybody should catch a case it's the white man who instigated the whole thing.
It comes down to the fine details. During the course of an argument, one party unholstering a weapon can be considered a "threat" and/or menacing, so can pointing at a gun on your waist or simply tapping it as a way of letting someone know that you're strapped. WIthout someone actually pointing it at someone, or actually discharging it, it becomes light weight, wishy washy not worth prosecuting; but people have been arrested for it, and it really depends on the City or State and how it's articulated with any after effects.
Using a gun due to a threat of a fist fight would depend on the details too. It can be considered the unequal use of force in a self-defense situation. Again, it might be different in Florida because they are pretty liberal with carrying laws, but in NYC they'd charge you before you could blink twice. But a lot of it comes down to who escalated the situation and how, along with whether the person being threatened could reasonably come to the conclusion that they were in a serious threat of a serious physical injury or death--it becomes very subjective in that case. A Jury may understand a
little old woman pulling a strap to a guy who throws up his hands, but another guy considerably younger who is equal weight, height, fighting ability etc etc probably wouldn't pass.
My guess, hypotehtically in this case, if the guy had of shot it, he probably would be charged with second degree homicide., but then again Florida has been really strange with this "stand your ground" law especially after that parking lot incident where someone was killed and got off for it.