It seems like this is starting to take on an always-carry-at-home theme, so I'll try to bring it back around.
The 15 year old kid was not carrying and repelled a home invasion with two shots from a .22.
Some thoughts -
1. Someone taught that kid to shoot and to be decisive. Good for him.
2. The .22 was probably already loaded and within easy reach. Again good.
3. In a Castle Doctrine state, which I assume Georgia is, shooting a home invader "in the back" will not likely be relevant as long as it's inside the dwelling.
4. Like all predators, BG's don't want to get hurt. Once the prey fought back, the other BG high-tailed it out of there.