motive has no relevance. anyone who discharges a weapon in your presence is a threat to your survival and it must be assumed that they intend to take your life regardless of who the current target is. the fact that they discharged the weapon in your presence is proof of that. if you were standing in a room with concrete walls with a guy randomly firing a weapon in any direction would your first point of concern be why he was doing it? or would you be more interested in taking action to preserve your life for fear of being struck by a ricochet?
1. you don't load a weapon unless you intend to fire it.
2. you don't point it at someone/something unless you intend to kill.
if you walk into a convenience store, pull a gun on the clerk, and demand money im not going to wait around to see if you intend to kill the witnesses as well. your actions are proof to me that you have 0 value in your life, mine, the clerks and anyone elses within weapon range. if you don't value your life, why should i?
i can point out about 50 instances in which that mindset failed miserably. while not the most heroic of options, those who at the very least barricaded the doors took action. which i might add, saved not only their lives, but the lives of everyone else in those rooms. had they ran rather than stand their ground and do something, there is a very good chance that they and several others from those rooms would have died as well.
while barricading the doors put them in direct danger as the nutjob fired blindly into them, they seemed to have faired far better than those who played dead, prayed they weren't the intended target, hoped he ran out of ammo, etc...
im not saying its fool proof or the safest of things to do. but given the option of taking my life into my own hands or putting it into the hands of a nutjob and hoping...