I just saw the entire video - the man was down on the ground, being restrained, and someone yelled, "He's got a gun". Shortly after, he was shot. I don't see how he could have pulled the gun on the police, lying on the ground, with a couple of cops on top of him. It's understandable how people could be upset.
The police overreacted, much like an untrained civilian.
I won't call it 'execution', but I'll call it a problem nonetheless- there's too many incompetent officers with a gun ho mentality.
It's becoming outrageously common that death occurs not by the absence, but rather presence, of officers.
Have we forgotten the oath of officers, or do we just give them a free license to kill now?