Depends on how you want to look at it. All three are co-conspirators. I think Islamic values are that you dont cheat at all, nor allow people to cheat off of you, and if caught, you tell the truth about what happened. Why is there concern for the muslim community or that they are from a muslim community, when these actions arent really "islamic" in nature?
I think many people would choose to tell the professor that others cheated off of them, to get less punishment. Plea bargaining is very popular in courts of law. As to what I would do, I wouldnt want anyone to cheat off of me, because chances are they will get a big fat F by doing so (since I dont study). grin