Yes. I know.
Just my thoughts. If threat was neutralized after 1-3 shots then what point is there wasting bullets on this trash? In a firefight ammo and cover are your priorities. How would you know he was alone? Guy was trained as a cop. All that training and experience go through his mind. Panic, adrenaline? Police are taught how to not panic. Seems fishy, but will suspend further speculation until more facts present themselves. Am likely wrong.
When the decision is made to shoot, the number of bullets is only a consideration when you have to make a magazine change. I never have just the one weapon with one magazine in my truck.