i used to work there, this story doesnt surprise me one bit. kudos to the kid for going back in there and confronting that POS crook, too bad he didnt shoot him, one less dumbass to be on the streets. he'll no doubt go attempt to rob someone else.
here's how AZ see's it, yeah, he saved them $2k (probably more if they were about to close the store for the night), but had the robber shot him or killed him, AZ would've been paying hundreds of thousands of dollars in medical bills or paying his family had he died. bet they looked at it as "we need to send a message that we cant tolerate this kind of behavior". even though had the kid not done anything, they could end paying for two employees being hurt or killed.
i think he should have gotten some sort of warning at the very most and more appropriately some sort of raise or reward.