S not feeling safe with roommate

I agree that your S handled things exactly right. Given their troubles, it was gracious of the the roommates mother took a few minutes to express her appreciation. Hopefully the roommate will get the help he needs.

You might mention to your S that if he feels he wants to talk to someone about the incident that he could contact the school’s counseling center and make an appointment. This was a highly charged situation and he may want just want to unload his feelings etc. on someone.