So because an innocent bystander might get injured (even though in many, if not the majority, of cases there is nobody else in the vicinity), the police should go ahead and summarily execute them?
Which is essentially the standard practice. Even though officially their training says they are supposed to be using less-lethal options if at all possible.
A shoplifting suspect actually pulled a gun on a police officer. But the loss-prevention officer and the armed police officer managed to immediately disarm and subdue the suspect without shooting him to death.