I disagree with him.
were I a firearms instructor, if a devout muslim wanted to take my course and pay the fee, I'd have no problem.
if he started spouting BS, talking trash about America, or otherwise acted in a manner not conducive to polite company, I'd refund his fee and ask him to leave.
same with a democrat/liberal/moonbat. I don't give a rats ass about your politics. you want to pay me to train you, I'll be happy to take your money. but if you start acting a fool, pretending your target is george bush and whatnot, then "I reserve the right to refuse service to anyone"
I vehemently disagree with the tenets of islam, but as a christian that has been on the receiving end of bigotry I will not do that to someone else.