It's true that parts do fall off planes now WITH certified parts. Can you imagine how many would be falling off if they were rickety parts bought down at the local hardware store.
This incredibly talented pilot deserves his medical, he likely prevented a much worse outcome and deserves a lot of credit.
What I find odd is that the CAA has provisions for pilots with two prosthetic arms. The only difference is that those prosthetic arms have to be constructed to aircraft standards. I view the prosthetic as a very important component in controlling the flight surfaces. About as important as the elevator mechanical linkages and aileron linkages, combined. For the CAA to not care how well a single prosthetic is built just bothers me. A lot. When is it most likely to be stressed by frequent pushing, pulling, twisting, etc. ? During the landing! When there's not a lot of time to implement a personal SOP, especially in adverse weather conditions.
I think I'd feel safer with a pilot who's landing with two prosthetic arms, knowing the clamps and linkages are as reliable as the rest of the plane.
And just to clarify, I view this to have NOTHING, ZERO, NADA to do with a medical, or with people who have a medical degree. It needs attention from mechanical engineers, aerospace engineers, and regulators. This is all about mechanical parts being airworthy.