I'm not sure where I said civilians don't have the right to be armed. If I did say that above, please correct me.
He had every right to be there. I have every right to yell "fire" in a crowded theater. He has every right to obtain an AR, underage, via straw purchase. Just because we have rights to do something, doesn't automatically make it legal (or smart). He has the right to defend himself, but you better believe his actions leading up to the event will be scrutinized and weighed.
He used unemployment benefits to purchase the weapon.
See here.
What a massive break, his lawyer is paying off with that development.
Again - big picture; he absolutely should have defended himself. I'm not saying he should have laid down and done nothing, that's absurd to imagine. But, should he have been there to protect stores with insured items? (Although, the insurance process can be a PITA). But, it's simply not worth escalation. Let's be real, he is a young dude pretending to be tacti-cool. If he truly believes in protecting and serving, he should have enlisted. But that option may be shot, by his own hand.