dervish:
.... yet he was allowed to pronounce on the supposed guilt of two men using equipment he knew nothing about.
In those few words you encapsulate the whole rotten mess that is UK Military Air Accident Investigation. It is done by those who are not trained Air Accident Investigators (trained Air Accident Investigators from the AAIB can be invited to give assistance to a BoI but only on its terms and direction). So the operator (ie the RAF) investigates its own air accidents and thus any of its own shortcomings. Even if a BoI managed to do so objectively it in turn is subject to review by Senior Officers and its conclusions can be overturned by their Finding, as with Mull. Their Finding then becomes inviolate in the absence of "New Evidence", the existence of which is solely judged by the same operator, as with Mull. Incestuous would be a polite way of describing this cosy arrangement!
If all this merely covered up the incompetence and negligence of the operator there would be those who would simply say "let sleeping dogs lie", I'm sure. But Air Accident Investigation has one all important purpose, ie preventing recurring accidents from the same cause. This the Royal Air Force Air Accident Investigation System has spectacularly failed to do, if only a fraction of the Fatal Airworthiness Related Air Accidents were caused by the revealed Systemic Failures of the UK Military Airworthiness Regulatory Authority, aka the MOD.
High time then that the Investigation of UK Military Air Accidents and the Regulation of UK Military Airworthiness be handed over to those who can, as the existing set-up plainly cannot.
High time we had a separate and independent MAAIB and MAA!
Self Regulation Never Works, and in Aviation it Kills!