The short answer is, yes, if you think they are a threat. In fact, **** yes, smash their ****ing face if you can, if they are threatening and carrying a gun.
Here is the problem with unbridled gun use (well, a problem, among many): once the bullets start to fly, or someone appears threatening and are holding a gun, how is anyone supposed to know who the "good guy" and who the "bad guy" is. If I saw someone running willy-nilly through the streets carrying a gun, especially if he had already started shooting, I am not going to immediately think "oh, that guy is obviously defending himself against multiple assailants, I better help him out". No, with limited knowledge of the situation you just walked into, the rational thought is "holy ****, this is an active shooter situation as we have seen and heard drilled into us time and time again, that guy it a threat!" And the rational response is to...well, it is to run away, but if you feel you can and need to help defend others, or if you are just a nihilist like me, then maybe you go in swinging hoping to bring the guy down, even if what you have available to swing is just a skateboard.
See, just like the whole problem with "arm-chair QB-ing" the police, that we cannot know what they were facing/thinking/feeling when they were in the difficult situations, the same applies here. We cannot know what these guys were all thinking. My bet is, most thought this kid with the AR was a threat, and they went at it rather than doing the rational thing and running away. Does not mean they deserve to be shot down.
