Didn't the OP say he applied the lock before he put the revolver in the bag?
Yes, but given the numerous people that don't trust internal locks one way or the other, it's surprising how many are pointing out the fact that he had it "locked" now. The lock is a mechanical device, and it can fail. Furthermore, the gun should never be stored LOADED and LOCKED. If it's locked, it needs to be unloaded. There is no good reason to lock a loaded gun, and several ways you could get yourself hurt by doing so.
Supposing the internal lock had failed or not been properly engaged, there are also many scenarios that could have resulted in someone getting killed. The OP's wife could have discharged a round while digging through the bag, or could have asked a child to retrieve something from the bag.
Gun safety is everyone's responsibility. It does not cease to become an issue when a gun is "locked," especially if it is loaded! Loaded guns should only be stored in a holster which blocks the trigger guard, and away from unauthorized access.
Is this approach excessive? Maybe to some. The gun
probably wouldn't have gone off even if unlocked. There's a
chance that it
might not hit anyone even if it did. I could go park my car on a hill and sleep in front of it tonight, and
probably be fine tomorrow. But when you're dealing with a tool designed to be as lethal as possible, there is no room for error. Why take the chance when you could have:
-unloaded the gun
-locked it
-informed your wife it was there or stored it somewhere else
all in about 15 seconds, and eliminated all possibility of an accident?