Don't pull a gun unless you expect to have both the intent and the willingness to kill.

As if the fulfillment of this condition makes it good advice to respond to verbal aggressiveness with gun threats. Worse still, someone who is actually capable of shooting people over lewd remarks would probably be considered too much of a psycho to have been allowed a gun in the first place. (Not disagreeing with you there, just pointing out that there are stronger objections to be raised against that recommendation -- from the point of view of legal consequences, not just of immediate safety.)