But increasingly, it’s clear that there was a conspiracy to keep it all quiet to avoid bad publicity and protect the Post Office’s reputation.
Some key moments that have emerged are really extraordinary.
In 2010, Rod Ismay the head of Product and Branch Accounting at Chesterfield, produced a report for a new MD basically saying Horizon was fault-free and branch accounts couldn't be changed by anyone except the sub-postmaster/mistress (SPMR) who was logged on. He was advised on at least four occasions subsequently that Fujitsu could change data remotely, but never told anyone or amended the report, even though people were being prosecuted for theft and false accounting on the basis that the Horizon figures were absolutely to be trusted.
One email with such a warning has never been disclosed to the inquiry and was deleted from Ismay's (and several other people's) account, although he denies doing it. The inquiry only knows it existed because someone cut and pasted sections of it into another email.
Ismay was concerned in October 2010 that a case involving a branch at West Byfleet in Surrey might undermine trust in Horizon because the SPMR, Seema Misra, was claiming a £75,000 'loss' was due to the faulty computer system.
On the eve of Misra's trial at 4:00 pm on 8 October 2020, Jarnail Singh, the senior criminal lawyer at PO handling the case, received an email from another PO lawyer Mandy Talbot telling him that senior managers, including Ismay, were taking a keen interest and wanted to know about anything negative that might crop up.
In an extraordinary coincidence, half an hour later, an email came in with a report attached explaining the 'Receipts and Payments Mismatch bug' which caused unexplained discrepancies in branch accounts and which might have offered Ms Misra a pretty solid defence. Someone downloaded the report onto Singh's hard drive and nine minutes later printed out a copy. He denies it was him and he also denies ever seeing or printing the report which could have saved Misra a nine-month prison sentence. The inquiry KC described his denials as a 'big fat lie.'
I honestly think Singh saw the report, realised its significance but said nothing, and didn't disclose it to the defence solicitor as he should have, because it damaged his case and he would have been in trouble with management. Having made the first step, he couldn’t afterward admit it and had to cover it up for years and is still doing so.
Later in 2013, a PO investigator, Helen Rose, wrote a report about an incident that took place at Lepton post office near Huddersfield when the SPMR flatly denied ever reversing a transaction involving a £76 telephone bill even though the reversal was made using his login details.
After some work, the five-page report set out how the system, Horizon itself, reversed the transaction without the SPMR's knowledge but using his username.
Incredibly, this was not a fault and was operating precisely as designed. It was only discovered by Fujitsu's Gareth Jenkins after a lot of painstaking investigation. Goodness knows how many other transactions were reversed without the SPMR realising it. Jenkins offered to modify the system to make it easier to see when Horizon did this but as far as I can see, it was never done.
All throughout this period senior managers at the PO were offering reassurances to the public that Horizon was absolutely fine and denying reports of miscarriages of justice..
Also in 2013, an external lawyer at Cartwright King learned that some unnamed people in the security team at PO were shredding documents including minutes of meetings and he wrote a piece of advice to Rodric Williams, the former head of litigation at Post Office Ltd and current Head of Legal telling him this should stop.
Williams kept the advice in his desk drawer for two weeks and never launched an investigation. It wasn't until his boss Susan Crichton discovered the advice that he drafted a reply to Cartwright King saying everything was OK and they always followed strict rules. He never asked where the information CK had received came from or who was doing the 'shredding.'
I am certain some very senior individuals are going to face serious criminal charges and some will find themselves in jail.
