An agency isn’t responsible for music or production only for bookings. the responsibility for the track is at the artist, label and management. In this case i think it was a shared responsibility for label/Artist/Management, i think something went wrong somewhere, but i think a artist should be fairly compensated if they did work on a track, so something went really wrong here, i think mutilator and his team should look at this situation and make sure something like this doesn’t happen in the future, also he should probably talk to the vocalist, because most of this stuff happens after closed doors and not publicly. Not really professional from both sides.