I think in a case like this any action subsequent to an officer yelling “gun” or actually shooting is easier for the latecomers to the shooting to defend. The first cop that reacts is going to set off a justifiable chain reaction in terms of other cops backing him up, since at that point they react as though the threat has been verified & is real. The pressure really is on the first cop who draws/fires; he best know what he is doing.
In a similar story, years ago an African immigrant was shot in NYC by detectives looking for a black suspect. They asked him to stop, and he approached them reaching for his wallet (I don’t think it was ever established that he spoke English or understood that they were looking for a perp). IIRC, one the cops fell off a stoop in the scuffle and broke his tailbone; when he reacted his partners thought he had been stabbed or shot, and they killed the immigrant (who wouldn’t respond to their verbal commands to drop what he held in his hand, or to get down on the ground). I don’t think those cops were ever charged with anything; it was an unfortunate but understandable chain of events.
I don’t disagree with you on that one.