It's obvious you've never had a job on the streets - as a law officer, EMT rescue, fireman, etc. Perhaps you should for your own education and service to your community.
Get over the term "slowly." If someone is trying to get a better shot, does it matter that they are moving their gun "slowly" over the target? No, it is the action that counts.
When a car driven by a suspect/perp moves after being told to stop, turn off the engine (there is a BIG reason for that command), and hold up their hands - EVERYONE in the area is in IMMEDIATE danger. It doesn't matter at what rate the suspect is moving the car - that the car is moving is the danger. Usually when a suspect begins to "slowly" move the car - they are doing two things.
One - they are beginning to really panic or have gone into the "zone" of where nothing matters anymore and it is time to take someone with them. Two - they are lining up the car for a better shot.
Either case is extremely dangerous and about to become worse in a hurry.
That better shot may mean a better way to run back into the streets to put someone else in danger but more often than not, the moving car usually means a suspect/perp has hit a point of uncontrolled violence. That slow moving car is going to head toward someone and could get real fast, in a big hurry. Someone is about to die. 2. Do you think a citizen, who saw a car roll SLOWLY toward toward him, could shoot to kill the driver and expect to be cleared of wrongdoing, because a slowly moving car is a deadly threat that merits deadly force? I don't.
It depends. Is that citizen able to get away and is the driver of the car slowly turning to get a bead on him before accelerating. The circumstances would decide. There have been cases of assault with a deadly weapon - a vehicle - in citizen cases.
But you are overlooking major differences.
A police officer's life is regularly assaulted as part of his job. The threat is higher than for the regular citizen. Thus, his latitude for reaction must be higher. No one is going to try to kill you today. But when a cop walks out the door in the morning, he knows someone is going to try.
Secondly, the area of responsibility is different. A citizen has only his own life to protect. A cop has his own life, his partner, the rest of the officers on scene, the people in the neighborhood, and the rest of the community should a violent suspect continue his crimes. In a situation such as the article describes, the scene and the suspect must be brought into immediate control - or there is an immediate threat to everybody in the area. Because the threat is not just to himself, but to the entire community, the officer again must have a wider latitude or reaction.
A car can accelerate very quickly. If a fleeing suspect has been told to stop, switch off the engine, and get out of the car, and he doesn't, then starts backing towards the cops - they can't wait to see if he's intending to hit the gas and run over them, because if he did, they'd be dead.
I had a friend who had both her legs and her pelvis fractured by a VERY slow speed collision in a high school parking lot. (Somebody backed out of a parking space without looking.) The sound of the broken bones grinding together as she tried to stand up is something I will NEVER forget.
While I agree that the threat is higher for a police officer, in terms of probabilty of being assaulted, but once the threat situtation exists, the ordinary person and the cop should have the same latitude for reaction. In some states, they do. After all, if the threat is carried out, they'll both be just as dead or just as maimed.