Most officers carry their gun off duty. I'll bet he had his badge with him as well. Police are never fully off duty.Apparently what has happened is that the officer overeacted in the situation, which makes you question how he will act/or acts in high stress situations using his gun in which his job calls for often. He was off duty, why did he have a gun with him, did he feel he might run into a life threatening situation that he may need to use a gun?
And guess what many of us have concealed carry permits and we are never on duty but more often than not are armed even when we are in a place that we aren't planning to be is a life threatening situation. In fact, if I thought I'd be in a life threatening situation I wouldn't go.