I think these guys did the right thing, they ended the situation without ANYONE getting hurt or killed. they responded to the threat with no time to think of company policy. I have been armed security/loss prevention officer for a while now, and I only hope if I am ever put in a situation like this, that I will be able to handle it in the same way.
Walmart does have some crappy policys regarding their loss prevention guys. I have a buddy that used to work as security for walmart, he was at that old walmart in MWC before they moved to location. He was a MWC Police officer. He had a guy that was stealing a bunch of DVD's. He confronted the guy as he was runnin out of the store, the guy pulled a gun and ran out to his car and took off. My buddy jumped in his squad car and started pursit. He was not chasing the guy because he was stealinng but because he pulled a gun.
My buddy got fired from walmart because they have a policy that states you are not allowed to chase a shoplifter once they make it out of the store