The fact that he went and slapped and kicked the guy after means he didn't realize he shot him....!, I'm pretty sure he was so out of it he thought the victim was pretending/acting out, so he got angry and went to deal with him....!!! Imagine being so drunk not realizing you shot someone...??? (I hope that's not going to work for his defence for a lesser sentence...).
This just shows how dangerous guns are, I think what lesson should be learned from this incident is, off duty officers, of any kind, should not carry guns... , at his state of drunkenness anyone could have picked his