Boy do I hope cops don't think the way you do. You don't use deadly force because you are afraid what someone may do. Perhaps, when he was in the act of ramming the police vehilce, you would then be justified in attempting to use deadly force. But once a vehicle is stuck, surrounded by police, why would you need to put 6 bullets in a guy?
This is the exact reason against using deadly force. The suspect is now dead, so we now only get to hear the police side of the story. I'm sure the police will do some half-assed investigation about the surrounding circumstances and clear the police officer. We will never know what led them to be justified in using force.
I work in a job where I see bad police work every day. I have come to be extremely skeptical about their tactics. I just have trouble with police ever using deadly force based on the extenuated presumption that the person has the intent to cause harm to others. Police know there is serious risk in their job-- so I have a hard time with them essentially saying "well we fired on the guy because we were afraid he'd hurt us."