I've purposfully avoided the PROTOCOL!!! arguement
Because you quite obviously know nothing about it.
as to me there aren't enough facts to prove otherwise there was an immediate threat to innocent life.
But there were enough facts for you to assume that the cops should have given the kid the benefit of the doubt and allowed him to pull a suspected firearm from his waistband wave it around a bit and claim "hey, it's not real".
Right. Sure. Dead on.