There was a lot of discussion about the holding of passports. It used to be the military policy hence the current GM was very keen that Horizon should hold all Passports. If it were not for the intervention of the old GM, then it would have been the Horizon Policy.
There was an incident with an ex PHS guy who decided not to stay on, and the new GM tried to have his passport held "until the completion of the clearing process". This guy had no contract with Horizon.
UAE labour law is a nice book that sits on a shelf, and outside of Dubai it is seldom observed. Horizon with its flight duty hours is breaking UAE Labour law.