We are all familiar with the old joke that an ‘Ex’ is a has-been, and a ‘Spurt’ is a drip under pressure, so an Expert is ‘A has-been drip under pressure!’

But at the Post Office Horizon Scandal hearings yesterday, the Inquiry’s barrister asked the Post Office’s Investigator, Steve Bradshaw, who had given ‘expert evidence’ at criminal trials, whether he knew what an expert was. He answered along the lines that he didn’t know other than an expert was someone who knew more than the ordinary person about the particular subject.

Wrong, Wrong, Wrong!! Because in the past – and seemingly in the recent past – there have been miscarriages of justice due to substandard evidence by ‘Experts’, the rules about expert evidence are very, very strict and quite onerous.

The reason is that an ordinary person can only testify as to facts* within their direct physical experience (indirect experience is not admissible as it is ‘hearsay’).  However an expert can testify as to opinion, and so their evidence must satisfy strict tests.  But first and foremost, their duty is to the Court and not to the party that paying, employing or briefing them.  There are many other duties, including the need to agree with the opposing side as much of the technical detail as possible, and to provide to the court a clear statement of areas of agreement and disagreement.  There must also be a ‘statement of truth’ saying that the statement represents the witness’s own true beliefs and that these duties are understood and have been complied with.

*[For example, an ordinary investigator can say ‘the computer showed that there should be £2,000 in the till but I only counted £1,500.’  He cannot say, ‘therefore someone stole £500’, because that is an opinion.  If he saw Fred Bloggs putting the money in his pocket, he can report that, of course, but he can’t say ‘I suggest that Fred Bloggs must have put the money in his pocket.’  I’m not an expert as to what is necessary to prove theft.]

I am rather shocked that such shortcomings were not found out in the criminal trials.  I have testified as an expert in a lot of civil and criminal trials and other hearings, and in my early days I was puzzled when a barrister asked me out of court, ‘What is the Question?’ Seeking clarification, he told me that there is a saying in legal circles that there is always a question that reveals whether someone really is an expert, and I have to say that more than once we caught someone out this way.  So I don’t see how the Post Office’s witnesses didn’t get caught out, though probably they sometimes did, because we know that quite a few cases got thrown out in the original trials.

People are scared of digging into technical details – they feel that their heads will spin and they will make a fool of themselves, so they don’t even look to see whether things make sense even at a simple level.

But in the case of the Horizon system, we do know that in its early days it just used an ordinary telephone line and these are inherently unreliable.  I know because I used them for remote monitoring of construction sites.  So transactions are logged onto the local computer and then sent to the remote server.  But this process can get interrupted or corrupted for any number of reasons and you have to make sure that nothing is lost or duplicated.  This is not straightforward: it needs sophisticated ‘handshaking’ to maintain integrity but it seems that deposits were sometimes duplicated.  You would think that withdrawals could also be duplicated, and it is strange to me that no-one seems to have had too much money in their till, although perhaps there isn’t much incentive to report this!

And it wasn’t just the database staff who could alter individual accounts: there was some sort of ‘automated’ connection with other banking systems too.

Apparently Fujitsu had a room full of people trying to correct errors every night, because otherwise the system could not be got up and running for business the next day. Moreover, problems with the system were recognised right from the outset, and were even reported to Government ministers.

So it beggars belief that they actually decided to prosecute people when the knew the system was faulty.  Of course, they wouldn’t want postmasters to think that they could get away with fiddling the books, but to send them to jail was bonkers beyond belief.  Although the recent TV drama brought the whole appalling saga to popular attention, there was already a Public Inquiry ongoing, but they still seem to be trying to obfuscate the issues – they still haven’t released all the documentation.

But the latest news suggesting that they had subtracted compensation costs from their profits when calculating their tax liability (which would be illegal) shows that they still haven’t realised the disaster that they have created for themselves.

In reality, the Post Office has lost its purpose and I don’t see how it will recover from this. Very sad after 365 years of service.  If only they’d ‘fessed up when it all started, maybe things would be different.