You are very correct and I was not trying to insinuate that the mere presence of a gun would have changed the end result.
No idea how the 2 became entangled so we have no clue if there was time and distance prior to entering the room where the victim could have brought their own weapon into play. There is a brief span there where the victim is able to grab a broom or something and try to fight. Would being able to access a more effective weapon instead of a broom resulted in a better outcome? Don't know, but I'm of the opinion that a gun would have been more useful than a broom; even if wildly fired in random directions (not at yourself though).
Video's like this really hit home just how unprepared most of us are. I lump myself into that category since its been a long time since my last fight. Definitely reinforces the whole figure out a way to budget some training problem.