As said above, if the Post Office said there was nothing to disclose, that would be the end of the matter.
If it was a Police investigation, they’d have got the lot, but due to it being the Post Office Investigations, they undoubtedly thought they could do what they wanted, as they didn’t play by the same rules as everyone else and didn’t see the need to.
I have to disagree with the above, and I will state the reasons for doing so below. But first, part of my working background before retirement. As a civil servant for over 32 years, in a Government Department (DSS) that paid out money to the public, I was part of a cadre of Management staff that were trained as 'Internal Investigators', to investigate financial fraud being committed by staff. We were trained way beyond PACE 84, the details of that I will not go into.
Now, the role of any investigator once given the bare bones of the potential fraud is to examine everything from all angles. A statement of the obvious, yes, but it appears that the POID (Post Office Investigation Department or whatever its further iterations were) investigator(s) did not go into sufficient detail to bottom out exactly what happened.
Furthermore, once the same scenario was headed up to POID on a regular basis, that should have alerted POID to the fact that there was regular fraud taking place in identical scenarios, OR that there was potentially something remiss with the financial accounting system.
Accordingly, (and this is something that the solicitors/lawyers of the accused should have latched onto) they should have applied the standard tools of any investigator:
1. ABC.
Accept nothing
Believe no one
Check everything
Doing this (starting with the proverbial 'blank piece of paper' and a totally open mind as to what has happened) would, I believe, have eventually put them on to the track of something not being right on a central/national financial basis. At the 'check everything' point, they would have discovered the computer discrepancies (whether that was found and ignored, or simply not gone into, I do not know).
2. Kipling
I KEEP SIX HONEST SERVING MEN
THEY TAUGHT ME ALL I KNEW
THEIR NAMES ARE: WHAT AND WHY AND WHEN
AND HOW AND WHERE AND WHO
Had the POID investigator(s) applied the above thoroughly, together with ABC, a pattern would have appeared over a period of time that would have been in no way consistent with individual fraud taking place at different times, in different places, all over the country. Their investigations would then have, necessarily, taken them down the path of computer malfunction rather than individual fraud cases. In truth, the investigator(s), and their
modus operandi, need to be investigated, and if they have falsified anything (knowing it to be false in the light of their proven investigation) in their ultimate submission of documents to any court hearing, they need to be prosecuted for perjury. That would also fall under 'serious misconduct' if still in the employ of the Post Office, and should result in dismissal. If they are retired, then their retirement payout would need to be reconsidered retrospectively in the light of their previous (now confirmed) conduct.
All of 'Kipling' and 'ABC' should have formed the strong defence of any solicitor/lawyer defending every single one of the accused, but it appears that did not happen. Also, there is no guarantee that the Police would have gone into such depth...
Apologies for such a long post, but I felt I should outline certain things, having worked on some big cases as an investigator myself. I can't disclose anything on those cases, as I am bound by Section 2 of the Official Secrets Act 1911 (as amended and updated) unto death.