I'm taking him to the range tomorrow to work with him, showing him that one hand is not a handicap.
I'm nitpicking...but it truly is a handicap. It's not impossible to work a semi auto with one hand, but it is far more difficult, and it takes more time than with two hands.
However, I agree that if you are limited like that, it is not impossible. It is very possible, you just have to learn to do it and practice, practice, practice.