It did last five seconds from the point guns were drawn and the suspect ignored and moved away from the officers. Everything else is secondary to that situation. It doesn't matter if what happened beforehand was an argument or a polite discussion, the moment the suspect ignores them he creates the problem.
No, I mean they have the right to shoot if they're not following orders
and their actions create a situation where the officer can reasonably suspect a danger to their life.
Just quickly googled protocol for a definition and the below is the first to come up:
Basically that. By opening the car door and leaning in, he created the situation for the cop to rightfully fire at him. No court or any body investigating that incident will blame the police for it, and rightly so.