That is why I have considered carrying a BUG. Say somebody does manage to get your primary, you would still be able to draw a back-up and defend yourself. As soon as I turn 21 and get a CCW, I will always carry a BUG. Just an LCP or something I can slip into a pocket. That doubled with an open carried primary would make a great combination. If a store is posted, then just lock the primary in the car and you're good to go!
But for now, I wouldn't mind OCing a small BUG in a crossdraw rig. It'll have to wait until I am home for Christmas break though, then I can start experimenting with carrying two guns.
Then it might get in the way of my extra mags, Hmmmmmm...
IMO, if a BG gets your primary, you're not going to have time for a BUG. Time yourself for draw and fire (There's some free smart phone shot timer apps. I use Shot Timer Pro). Whatever time it is, I gahrohntee it will be slower than a BG moving his trigger finger. The only time it'd help you is if you were struggling for the weapon or you managed to get to where you could defend yourself from cover. Not worth carrying a BUG for everyday use, IMO.
If a store was posted, why wouldn't you just cover your primary instead of going to the trouble of walking all the way back to your car? As for extra mags, I agree with the adage "Anything you can't solve in six shots, you can't solve with a handgun".
Now, on your original question, I agree with others. Training for situational awareness will save your butt 10,000 times more often than needing a BUG, 1000 times than needing your primary, and 100 times more than a 10th degree black belt on the off chance a situation even
happens. A lot of us carry not necessarily primarily for the defense in and of itself, but because it reminds us to be situationally aware. That means being aware of the BG who sees your sidearm and gets way too close.
Ask yourself every 5 seconds:
"What's wrong with this picture?"
"Where are my blind spots?"
"Who is looking at me or trying to look like they're not looking at me?"
"Who is not returning my friendly smile?"
"Who is being way too friendly and getting way too close for no good reason?"
Etc., etc.
You said, "I know Karate schools teach how to disarm a person with a gun and I am going to continue to train this with my girl and other family and friends." I don't quite follow you. Do you mean you'll train your family and friends how to disarm a person with a gun or how to defend against someone trying to disarm you?
I'm sure you've heard of the 21 foot rule. IMO, once someone is within that 21 feet, you need to rely on other/additional means than drawing your gun. So, yes, do train on other CQC techniques. If someone has the drop on you outside the 21 feet, your ****'s pretty much ****ed. From what I heard in the newscast you posted, the robber had his own gun drawn and was robbing the victim
of his firearm. He lost it because the BG had the drop on him, NOT, as the story reports, "because he fumbled with his holster". He's lucky he wasn't shot while "fumbling with his holster". Without advanced defensive handgun training AND an opportune moment no primary or BUG in the world will save you if someone is intent to shoot you and they're drawn before you see them.