An unacceptable MAR recommendation from an Independent Safety Advisor needs some pretty good mitigation in order to receive a RTS. In this case such mitigation was not forthcoming. If anybody feels that they could provide such evidence that would satisfy the process by which the IPT is required to adhere, well they should submit the GEMS and be several pounds richer!
Service Deviation/ TCs or CLEs can and have been provided in the case of UORs where there have been unacceptable MAR comment, however that is not what is required for the Mk3 Chinook.
Remember also that it is not just one single Unacceptable comment but a host of them that is being addressed by Fix to Field.