B Noise
Your post ably demonstrates many people in MoD knew of this problem and how to avoid it. MoD's entire case centres on alleged ignorance of all concerned, blaming Martin Baker.
There are a number of inspection methods that would have avoided it. But the SI report opines the lock nut was cranked down so tight it cut new thread on the bolt. This would be easy to prove, but they don't try - they just leave it as an opinion. But you can FEEL yourself cutting new thread. It is a warning something is amiss. I suspect it was the first thing noticed by the engineer who looked at it during the investigation, yet omitted.
I asked before; I wonder if the lock-nut was new? A relatively recent maintenance regime meant it was removed more frequently (every 50 hours) so the obvious question, again not asked by the SI, was if extra provision had been made to ensure more spare nuts. A minor detail to some, but the bane of a maintainer's existence.
Was there a self-certification regime?