EWJ FEB 59 2025 web - Flipbook - Page 33
The Post Office Horizon IT Inquiry
Report:What Recommendations
Should it Contain?
by Dr Stephen Castell CITP CPhys FIMA MEWI MIoD, Castell Consulting
Dr Stephen Castell is an award-winning software and systems consultant professional, IT and
Law pioneer, and FinTech visionary, active as an international expert witness in major complex
computer systems and technology development disputes and litigation, including the largest and
longest actions to have reached the English High Court, and appointed in the ongoing highprofile FTX, Voyager and Binance US Class Action cryptocurrency lawsuits.
Email: stephen@castellconsulting.com
http://www.e-expertwitness.co.uk - https://archivesit.org.uk/interviews/stephen-castell/
This faulty forensic equating of ‘reliability’ with ‘admissibility’ was entirely at odds with the professional
expert conclusions and recommendations of my carefully researched HM Treasury studies. Indeed, from
the early 1990s onwards, in published journal articles,
I have consistently said “A trial relying on computer
evidence should start with a trial of the computer evidence” (see for example Computer Weekly, 22 December 2021 https://www.computerweekly.com
/opinion/A-trial-relying-on-computer-evidenceshould-start-with-a-trial-of-the-computer-evidence).
Introduction
In 1999 the English Law Commission (ELC) put in
place an astonishingly egregious legal construct – the
unfortunate introduction of the incorrect ‘legal presumption of the reliability of computer evidence’. That
wholly mistaken ‘presumption’, still legally operating,
was the defective bedrock on which the British Post
Office founded its unsound legal actions and private
prosecutions in UK courts against hundreds of innocent Sub-Postmasters and Sub-Postmistresses victims
(SPMs). These criminal and civil court trials, over
twenty years, relied on unchallenged computer evidence from the PO’s knowingly faulty Horizon computer system – arguably the ‘greatest miscarriage of
British justice’ in the past twenty years.
To re-emphasise: that twenty-year PO Horizon
miscarriage of justice was made possible through unchallenged, confident dependence by the PO’s lawyers
on the ‘presumption of the reliability of computer evidence’. However, any legal presupposition of the
trustworthiness of computer evidence is, and always
was, fundamentally incorrect. The ELC’s faulty introduction of that presumption arose through a misunderstanding and distorting by the ELC of the
recommendations that I set out in my 1980s Verdict
and Appeal Studies for HM Treasury into the legal and
evidential reliability and security of computer software
systems and technology (published as Castell, S., 1990,
The APPEAL Report, May, Eclipse Publications, ISBN
1-870771-03-6).
The Professional Duty to disclose all evidence on
which a litigant relies
In the handling of many of the PO Horizon court
actions against SPMs the situation was actually much
worse than simply the reliance on the faulty ‘legal presumption of the reliability of computer evidence’. In a
great many cases there was also a separate and distinctly egregious professional dereliction of duty by
lawyers involved in pursuing those trials on behalf of
the PO, which reliance by the PO’s lawyers on the infamous ‘presumption’ did and does not excuse (and in
which the ELC had no hand). That professional dereliction of duty by lawyers was this: in those hundreds
of appalling private prosecution and civil litigation trials pursued against innocent SPMs, there were no substantive or successful submissions made by the lawyers
involved that all the computer evidence on which the
prosecution relied must be disclosed, for (expert)
examination, challenge, and potential rebuttal.
Following my recommendations, the admissibility of
computer evidence in court was introduced into law,
by way of PACE 1984 (before that, such evidence
risked being inadmissible and/or treated as ‘hearsay’).
That was later wrongly mangled by the ELC into its
1999 ‘legal presumption of the reliability of computer
evidence’ (for details of that mangling see Christie,
James, 2023. ‘The Law Commission and section 69 of
the Police and Criminal Evidence Act 1984’, 20 Digital Evidence and Electronic Signature Law Review
62 – 95, https://journals.sas.ac.uk/deeslr/article/view/
5642).
Why did that full computer evidence disclosure not
happen, when there is, and always was, a fundamental duty to disclose at trial all relevant – in this case
pivotal – evidence, documentary or digital, on which
a party relies? That fundamental duty clearly arises
under Part 31, Civil Procedure Rules 1998, for Civil
cases, and also, as Andrew Marshall, a partner at
solicitors Edmonds, Marshall, McMahon, has noted,
under the Criminal Procedure and Investigations Act
1996 (‘Private prosecutions after the Post Office
scandal’, Solicitors Journal, March 2024, page 18
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