Re: Religious Restrictions on Training
The degree of problem really depends on the gender ration in the dojo. I have yet to train regularly in a martial arts club where women were not a very definite minority, and, given the typical class size at my current dojo, it would be easy to just avoid women. I'd say let him train.
It might also be a good idea to find a discreet and polite way to educate other dojo members about the situation. Otherwise people might start thinking he's a real jerk because he won't train with women. Assuming they notice...