Alan at SnarkyBytes has an interesting post about the 4 Rules and how rule 1 cannot always be applied. His post and the comments make a starting point for discussion.
N.C. Hunter safety has “Always point the muzzle in a safe direction.” as their primary rule, and if I was writing gun handling rules, I would probably start with that one. There are several circumstances where all of us handle guns and while we always check the chamber and magazine, after that we act securely in the knowledge that the gun is unloaded.
Out of this nettle, danger, we pluck this flower, safety.
— William Shakespeare, King Henry the Fourth, Part I