Why? He did his community a great favor... unless of course he believes this was the only time this POS committed armed robbery.
You have to say that to keep from getting prosecuted these days, even if you were the one being robbed.
I'll bet if he would have said: "The bast*** got what he deserved; and I'd do it again if he walked in tomorrow and pulled out a gun!" he would have been brought up on charges -- probably a weapons violation, or violation of the robber's civil rights.