yeah, you summed it up pretty well. As you pointed out, it is easy to armchair-quarterback, but the handling of this situation seems to leave a lot of room for improvement.
I am always amazed at how well things turn out when armed citizens take action to defend themselves. It is really common for citizens to do tactically dumb things, or even legally dumb things... and yet in the vast majority of cases, the citizen is successful in defending themselves. Even with poor marksmanship, and with weapons they are fairly unfamiliar with.