in your opinion do you think this person had a mental problem? i am not assuming anything you are the one that admits to assuming.
in your opinion is he swinging the rifle while the commands are being said? YES they shot very quickly but it seems they always shoot quickly instead of getting shot when the gun moves or the hand goes toward the gun even you are shot.
You were the one on the phone with him that is how you know he was on the phone?

or maybe it was a documented call time that we can see?
id like to propose a uniform that would absorb the bullets so the police can let the criminal shoot them before they shoot them back. (of course this wouldn't save any of the missed shots but hey can justify the shooting right?)
only issue is getting around in such a suit might need to use a hoverboard type of technology.