the more i think about it the more i agree with you, i know if you do a check ride in a sim you dont have to have a medical, not sure if the I/R can be done in a sim, i have my ATP check ride coming up, and i know i dont need a medical, i have one but its not required.
As you say if he flying in an aircraft he will be using his licence, therefore i would say he does need one. i think your right mate