Good post except for your very first point. If this officer had had his routine interactions reviewed much more vigorously by his superiors someone might have figured out he doesn't handle things well long before someone died. OR maybe not. What makes it so tough to convict a cop is that he is in these situations all the time. He might get 999 of them right, but than that one night his eyes and brain missed a beat and someone bringing his hands up into sight appears to be someone coming up with a weapon and in that instance you make a lethal error. Murder? Manslaughter? If we hold the police to such a standard that their one mistake lands them in prison, no one ever wants to be a cop.