Yeah man that really sucks that it happened to your friend. Unfortunately they had the right to do it because essentially they own the dorm. Though I know in my state Police officers can't enter a dorm room without permission an RA certainly can....at least thats around here, I don't know about your campus. Also he willingly let them in and willingly, though remorsefully, gave up that evidence. Something similar happened to me once. If only I had told the police officer to get a search warrant before he entered I could have literally gotten out of it. Next time your friend or you are in a situation like that and you know there's no time to hide it unless you buy yourself some time, ask for a search warrant. It could save your life.