However, some of the players did admit to underage drinking, so, in actuality, a crime did occur.
I would expect that if a serious crime took place, witnesses would and should reveal all they know. If no serious crime took place and one was present at the time of the alleged incident, by the same token, reveal all they know and not simply clam up.
The DA has said that if he doesn't start getting cooperation, some may be charged with aiding and abetting.
Duke should tell the players (witnesses) to cooperate fully or they will be in danger of losing any scholarships and may be subject to expulsion from the University.......regardless of whether a crime took place or not.