Circumstantial evidence points to a severe overreaction from the officer.
I did read somewhere that the officer only had two hours of de-escalation training which really didn't seem like much for a guy who carries a gun. . I'm curious if this is the norm or not.
In many controversial police cases while many just see a cop on a power trip, I tend to see a poorly trained officer who is a bit intimidated and trying to compensate for that with greater assertiveness which manifests itself as aggression. This makes the suspect feel defensive, and then the cop gets even more intimidated by the defensiveness and subsequently becomes more aggressive, making the suspect even more defensive.....etc and then shit goes bad.
What kind of de-escalation training is in place for people who are trained to carry guns? Does it come close to the amount of time they spend on firearms training?
As JulesVern pointed out, like them or not, the job looks like it has many encounters that can be intimidating. Do they get much training in this area?
I have no idea what is the norm for that, but this doesn't even seem like one of those situations. The guy said he had a gun and then starts reaching for something.
Now the cop has two choices, tell the guy to stop, assume what he is reaching for is not the gun and take the chance that he is wrong (and potentially get shot himself), or he can assume the person is reaching for the gun and not take that chance.
I know which choice I'd make and I don't want to second guess his.
The really important lesson here (and has been seen time and time again, but people never learn) is it is generally a good idea to listen to police officers and do what they ask. If they really are wrong, deal with it after when it won't get you killed.