In this case, no gun would have helped unless someone happened to have a sniper rifle they could shoot back with or bazooka or rocket launcher or whatever... Essentially just owning and carrying a gun for self defensive would not have helped in this case (or many others).
Understanding that it was guns that also ended this what is missing from most peoples description.
That's a fair point, but as I mentioned in my post, there's a place for highly trained professionals (such as Detroit Threat Management) and a place for everyone else. Even then, lethal force isn't always the only option.
Have they conclusively determined yet if he took his own life or was taken out by the police? I've heard conflicting reports.
Granted. Education and training is crucial. I would dare say there are plenty of private gun owners who have just as much if not more time behind the sights than LEOs. Also, still, as you stated, lethal force is not the only option however in any case where the subject is clearly threatening human lives, it is. My opinion.
They have ruled it as a suicide, but there are many differing theories on this.