Well, in the first place it's anecdotal, and therefor simply proves that there was one asshole, who apparently had some training, who didn't heed his training and fired blindly through a door. Sorry, but I don't know what the heck that's supposed to prove, and it certainly has nothing to do with the concept of concealed carry, which is all about deterrence.

So we have a man, presumably a gun expert who knows all about guns and gun safety, armed with one of his own guns in a store loaded with guns, and he responds to a threat by shooting his son.

How again do guns make situations safer?

Again, and I'm not sure why this even needs to be pointed out, the whole point of a concealed carry law is that it raises the uncertainty, and therefore the cost, of predation. You mean to say you don't understand that? Why not? Rocket science, it's not.

Odds are that only about 1% of those who carry concealed will ever use their firearms "in the gravest extreme." Why don't you do some reading on this topic, besides the odd anecdotal news report?