I read page one and not all the posts in between.
Doesn't sound like he drew it at you, so I'm not sure why you were shaken up other than the fact that your dog could have been shot? I had a friend recently come over to my house, he has a concealed weapons permit. I didn't know, didn't ask, didn't bother me. We started talking guns and he pulled his from his chest holster to show me without warning(I had no idea he carried or owned it at the time); nothing wrong with having a gun around as long as it's not pointed at me!
I may wrongly assume in this situation that it is not an area where dogs are supposed to be off leash? Either way really, a dog charging a man barking gives way for him to interpret it as he wants.
He could have easily told you he was carrying and let that be that, in most places while it is frowned upon, it is legal to disclose and show? a concealed weapon that you're legally carrying. Perhaps he hoped that showing you would make you realize how close you were. Either way he was in no wrong letting you know he had it.
I am taking a CCW class this winter and I'll be getting my permit when I turn 21. I would certainly use it in the same case if a dog was running at me in what I interpreted as aggressive had the dog not responded to a recall. Likely, that's all that saved your mal in this case.
Not sure why the opinion is that this man shouldn't own/carry a gun, sounds like it could have almost "saved" him.