It depends on the disability, I know.
However, in this case, the gentleman is an amputee, missing most of his left leg. He is right handed. At first, he thought of a shotgun for home defense, but further discussion prompted a concern that if awoken in the night, it would be difficult for him to manage a shotgun and maintain his balance.
Much discussion later, we came to a conclusion that a hand gun, in a quick access vault (there are kids at home) would be more manageable. Then we had to look for the best options. For a man who must balance on one leg, in the middle of the night, the conclusion was that shooting one handed, with the non-dominant hand, would allow him to balance on one leg, and use his other hand to help balance.
It was an interesting exercise in physics and balance and counterbalance.
As instructors we need to be prepared to think outside the box to help students find the solution that works for them.