The roommate was in the room part of the time. He said he was asleep and kind of drifted in and out of sleep and then got up and left. He did not participate in any part of the crime. It's not illegal to be asleep in bed and someone else is doing something illegal. His defense could easily be he didn't know a crime was being committed -- remember he didn't see them carrying her into the room, he didn't see her drink, he didn't know what condition she was in, he was asleep in the top bunk.
Should he have helped? Yes, but he admitted on the stand he was scared. That's not a crime either. The state would not be able to successfully charge and prosecute him with anything. I'm not comfortable painting him with the same brush as the others.
Thanks for the clarification. I was't sure of the (bbm) facts you listed. I thought perhaps he was in the room, saw her unconscious body being carried in, and witnessed/listened to the multiple rapes.