There is a situation, while fighting, your opponent falls down and draws out a gun. He is on the ground and you stand up. What is the offered solution for such a situation? Is there any? Is there a way to control or retention of the opponent? In Krav Maga, there are several techniques for situations that the opponent threats with gun, but you both in standing position and the gap is relatively small. Is there any solution for the case I mentioned before where you stand and the opponent in the ground holding gun? Demonstration videos are welcome.
You have very little to work with here. The solution is probably arguably usually to raise your hands and try to placate him "OK, you won, whatever you want, man". If he started the fight by being in a psycho rage, or you think he's on drugs or a gangbanger, i.e., you think he's going to shoot you, and you're more than a few feet from him, pivot, duck, run, and zigzag. It's hard to hit a target with a pistol if you're adrenalized. Even that trained officer who got in a good stance and shot/executed that limping-away guy in the back in South Carolina in 2015 missed one or two of his ~8 shots.