My feelings are, if you can't react in a calm, deliberate and lawful way, you shouldn't be carrying a gun.
I suppose this is all fine and good if taken on it's own, but the man in question here had been ROBBED at GUN POINT mere seconds
before this altercation with the LEO, and was at this point given a knee in the back and was in fear for his life.
There is no "calm, deliberate" anywhere in this scenario. He wasn't eating a ham sandwich on a park bench while sipping tea and feeding the ducks here. He had just been set up, attacked by a man with a gun, fired shots, RAN, and only then was detained by the LEO who didn't come from a marked car and apparently wasn't dressed as a uniformed street cop.