Just to correct one detail: he didn’t go through 911. He had a number that took him directly to a police dispatcher.
Interesting tidbit.IMO this is indicative of a guy who took his job seriously and wasn't out to administer any kind of "vigilante justice".
all police calls 911 etc, go to the same operator dispatch.
If a gun was being displayed, how did an attacking person have the ability to jump on top of that person? logic would indicate if a gun was being brandished/displayed a person would move away from the displayer.