Scottie, forgive me if I should seem just the least bit sarcastic here, but I've just spent 11-plus hours today teaching an immersion course in rules of engagement for private, armed citizens, and finished dealing with some stuff on an aggravated assault case at day's end, so bear with me here if I'm a little short on BS tolerance tonight.
You didn't mention if your friend actually carries or not.
If he is an unarmed citizen, and is giving you this BS excuse as to why he is not armed, it's not my place to judge him. Some people can protect those they're responsible for. Some can't. Those who can't seek face-saving excuses.
If your friend keeps a gun for home defense but doesn't carry, he clearly doesn't grasp the subtleties of the "higher standard of care" principle. Doing what you were professionally trained to do is solidly defensible. Ignorance is nowhere near as defensible. Any layman in the jury pool knows that "ignorance of the law is no excuse." At least your friend is not putting himself in legal jeopardy, having a gun at home but not carrying. But he is, of course, missing a very important defensive option.
And if your friend carries a loaded, concealed handgun in public in a place which requires a permit for that, and gives you the BS excuse you describe...well, his thought process may just be past hope of correction. He has made himself a criminal.
Hoping this has been responsive to your question,