‘Give your opinion, not someone else’s,’ Post Office Inquiry counsel tells experts

‘Don’t let anyone put words in your mouth.’ So declared Emma Price, counsel to the Post Office Horizon IT Inquiry, to expert witnesses gathered for Friday’s annual Bond Solon Expert Witness Conference.

Price, of 5 Essex Chambers, spoke about the lessons for experts of one of the most far-reaching miscarriages of justice in British history. She dwelt in particular on evidence given by Fujitsu engineer Gareth Jenkins, architect of Horizon, in a string of sub-postmaster prosecutions.

Jenkins admitted to the inquiry that he ‘did not appreciate that he was acting in the capacity of an expert…and did not understand his duties as an expert because they were not properly explained to him by those instructing him’, said Price. Jenkins also admitted to the inquiry that he changed crucial expert court testimony at the request of the Post Office during wrongful prosecutions of branch operators.

Expert witnesses ‘owe a unique, elevated duty to ensure that they do not mislead the court, regardless of the impact this may have on the party for whom they have been called’, Price reminded delegates.

She also stressed the importance of experts actually understanding what their instructions are. ‘You are reliant upon the party instructing you to give you clear instructions about the task you are being asked to undertake,’ she said. ‘In my experience as counsel, the quality of expert instructions varies hugely.

‘So ask yourself, are my instructions sufficiently clear? What is the context for my report? What is the scale of my report? What specific questions am I being asked to address? Have I been provided with all of the material that I need properly to assess the case? If, as an expert, you feel your instructions are insufficiently clear, ask for clarification.’

She added: ‘The court needs to have the full picture. Include everything that is or may be relevant to your conclusions from the outset. There may be factors which you have thought about, but have discounted as not being material in the case. You may have really good reason for reaching that conclusion, but you need to give that full picture.’

Another lesson of the scandal is to ‘give your opinion, not someone else’s’, she concluded. ‘Hopefully this goes without saying. Discussion with the instructing party and conferences with counsel, fine, but don’t let anyone put words in your mouth. Unless there is a good reason to depart from your opinion, don’t. Remember that you hold the pen on your report. Allowing others to edit your draft is fraught with danger.

‘Everyone in the this field - experts and those instructing them alike - can learn from what happened in the prosecution of the postmasters. And we should all be mindful of the potential dangers of expert witnesses acting in the mindset of partisanship, not understanding or adhering to their duty to the court, and being unsupported by those who instruct them.’

Inquiry chair Sir Wyn Williams has said the final volumes of his report, which will encompass the role of lawyers, will be released together. Price said the process is in the ‘final writing stages’ and these will be published ‘very soon’.