I have always been surprised that little has been made of the fact that in the wreckage the co pilot's intercom was found to be in the emergency position.
It is possible that there a crew communication problem at the critical stage. The copilot would have been responsible for navigation.
Also, regarding UFCM, I understand that the fixing of a critical part of the flying controls on the aircraft (the control pallet) had previously proved to be suspect and had actually detached, or partly detached on another example. This appeared to have been largely dismissed, although it was found to be detached in the wreckage, probably because of the high impact forces experienced during the accident.
Gp Capt. Pete Crawford, at the time the Station Commander RAF Odiham, commented that the very high speed cruise climb was not a recognised technique in the Chinook (or any other helicopter I've ever flown because it makes no sense). My interpretation of his comment was that he couldn't understand how the aircraft got into that situation because it was illogical that it was deliberately flown in that way.