Coz, what are the rules about sampling a track that already has a sample of another track in it? That is like making a derrivative work of a derrivative work.
Usually the initial sample license would not cover the third artist sampling it, would it? I would imagine that Be is owed for his lyrics and voice. And I would imagine that anything Be sampled that is in the "sample" that these guys took would be owed to their perspective owner.
So artist #3 owes artist #2 and #1 (owes/must get permission/license/whatever), right?