For the last 15 years I have worked in QA and Continued Airworthiness starting in the RAF and then in a variety of quite different aircraft maintenance and management "organisations" (some are not organised).
In ALL these organisations the same rule for QA/CA applies:
Nobody believes the internal company report is worth doing anything about - or that the QA guy's worries are just nit-picking pedantism.
If QA want some movement in a particular issue they will probably tell the next external audit team (and sometimes a regulatory authority) - for them to find the issue in their reports. If an external audit (or regulatory authority) finds the issue - something MAY get done.
The same principle applies to the MAA, and probably to the MAAIB too. There will be very little incriminating evidence from internal investigations and any possible incrimination will not be published in public records.
That is not to say that there will never be a case brought to some form of Trial - in all deep MOD rule-changes there has always been one show-case to show that the rules work and that there is no sham, but none afterwards...
If this principle is applied to the procurement system I can't imagine the potential for smoke, mirrors, missappropriation and abuse.