AA, I don't struggle with it at all.
We are going in circles again, but there was evidence that the aircraft was not fully serviceable. The type in general was not fully serviceable and it could certainly be argued that had common sense prevailed it should not have been flying at all, until all doubts had been completely resolved.
Whatever happened on the flight (and no-one knows, we can only theorise), there was certainly negligence at a higher level. There WERE another options (civvy air or even postpone / cancel the flight), and it could be argued that the RAF failed in its duty of care to the passengers and the crew.
Someone in higher authority made a very poor decision by insisting that an aircraft without a C of A clearance (and actually grounded the previous day by the very department responsible for introducing it into service) should be used for the flight, or any other.
The pilots, having been forced into a corner and paid the ultimate sacrifice, have shamefully been scapegoated by their superiors.