The guy in the video now works at a gun store! From what I understand, the bg did not survive...
To answer the OP's question.... Yes, you can shoot the bg robbing the store. That is the legal answer. In Texas, we are authorized to use deadly force when a felonious act is committed on us or a third party, ie. robbery, rape, kidnapping, being held against our will, etc. The key is the we DO NOT know what is going to happen. Legally, you can shoot the robber in the back as he's holding someone at gunpoint because that is a life threatening situation.
Now, just because we can, does not mean we should. I am a firm believer that any citizen being threatened with a weapon, should meet that force with an overwhelming action of force. Thanks to Front Sight, I'd rather act than react.
But, just because Texas law states that I can shoot someone fleeing my home with my property at night time (but not in the day time ), doesn't mean it's what I should do.
I think many of us, including myself, have "hero" thoughts from time to time, and that's ok. It makes me very angry and sick that some crackhead or meth addict can walk in to my neighborhood, my convenience store, and just take what he wants at gunpoint. So, playing it out in my head, is it self-defense or revenge?
I was car-jacked and held against my will for almost 45 minutes while they went ATM to ATM because one ATM was down and one only had $100. Had I not taken action, I probably would not be here today.
Every situation is different. Most robberies end without violence, but from time to time someone, or everyone, gets shot.
If you choose to get your permit, please spend every free moment asking questions, researching and understanding the law. And above all else, safety. This is a HUGE responsibility, not only to ourselves, but everyone around us. One mistake could end the life of another human being. Good luck!
P.S. Sorry for the rambling!