Which one is guilty of assault?

[Johnny Cupcakes]

If someone attacks me like that, they should be prepared to be shot.  Not because I think that shooting him would be necessary, but I'm not going to take the chance.  Although I think that those two security guards could have ended the situation without the gun, they didn't know exactly how insane this insane dude is, or what level of force should be used to stop him.  The security guards were guilty of nothing, but they probably need more training with firearms if they're going to carry them.  That dude almost killed an innocent person with his shot.

It's easy to judge all of the actions by watching the video a couple of times, but all of that going down in real time is quite the different story.  I don't really know what I would do, but if I had a gun, I may have used it in this situation.