Hi Red,
From what you say, it sounds like this student was singled out and made an example of, but hopefully not because of being male. I wonder if there may not be more to his story especially since you report that other students were in violation of the dress code too. Either way, I believe you gave good advice to "take it on the chin" and keep going. He may have recourse within the school admin. but following that route will likely cause the instructors to put more pressure on him. If he wants to complete the program more than make an issue over his alleged mistreatment, he will fall into step and work hard. Right or wrong, it will be the shortest path to follow and get him to his goal of becoming a nurse.
Thanks for writing,
R