According to Lord Bingham, only a small number of witnesses lie in commercial litigation cases and the overwhelming majority provide honest evidence based on genuine recollection rather than deception, regardless of how sound that recollection may be.

This raises a question, as posed by Lord Justice Popplewell in his speech “Judging Truth from Memory: The Science”: How should the judiciary decide between different accounts when conflicting evidence is given honestly?

Shift in courts approach

In circumstances where documentary evidence is silent or inconclusive in assisting fact-finding, commercial litigation requires courts to examine a state of mind of the witness. However, if the witness’s state of mind is hazy, perhaps because time has passed or their recollections have altered due to changes in experience, the fallibility of memory becomes more apparent. This is because human memory is fluid and changes over time.

Historically, courts have been reluctant to rely on the science of human memory when reaching their decisions. However, a shift in the judiciary approach has recently been observed.  

Gestmin SGPS SA v Credit Suisse (UK) Limited [2013] EWCA 3560 (Comm) (“Gestmin”) and very recently, Jaffe v Greybull Capital and others [2024] EWHC 2534 (Comm) (“Wirecard”) and have been two cases where courts acknowledged fallible nature of human memory.

Gestmin Case

The case involved a professional negligence claim where Gestmin alleged that the investment advice provided by Credit Suisse Securities (Europe) Limited was negligent. Gestmin asked the court to award damages for the loss suffered as a result of investing EUR11,150,000.00 in an Initial Public Offering of shares in a company.

When approaching the evidence in Gestmin, the judge considered scientific research on human memory, acknowledging its unreliability and the resulting impact on allegations and oral evidence based on recollections of events from several years prior.

The judge further added that human beings are often unaware of the extent to which human memory can be unreliable, highlighting the two common misconceptions. First, the stronger and more vivid someone’s feelings or experience of recollection are, the more likely the recollection is to be accurate. Secondly, the more confident one is in their recollection, the more likely their recollection is to be accurate.^[1]

While taking these scientific considerations into account, the judge reached their decision by placing greater reliance on documentary evidence rather than on oral recollections of conversations.

Building upon Gestmin,  Simetra Global Assets v Ikon Finance Ltd [2019] 4 WLR 112 (“Simetra”) further illustrated the evolving judicial approach. In Simetra, it was held that internal communications such as emails or instant messages should carry greater evidentiary weight, as they often reflect true thoughts of a witness at the time.  

Accordingly, it may be more appropriate to rely on facts established from documents rather than solely relying on witnesses’ recollections. However, this does not mean the judiciary should only rely on documents, given that in Wirecard case, documents were treated as interpretations rather than live transcripts.

Wirecard Case

The case involved an allegation of fraudulent misrepresentation made during a meeting that took place eight years earlier concerning the source of funds injected into a company. Recollections of the witnesses about what was discussed during the meeting were conflicting. Explicitly, witnesses admitted this by stating that their memories were hazy and hence, potentially unreliable.

When reaching her decision, the judge did not focus on the witness credibility but rather assessed whose recollection of discussions were more accurate.  In doing so, the judge turned to scientific reasoning to consider what factors might have impacted on the memory of each witness. The judgment was made in favour of the defendant, with weight given to the defendant’s argument that if the defendant had lied at the meeting, they would likely remember doing so. In relation to the claimant’s witness, the judge draw distinction between “live transcription” and notes prepared after the meeting by categorising the latter as “not word for word” therefore were interpretations.^[2]

So, what is the court’s stance then in relation to the accuracy of witness testimony?

There is a growing recognition that human memory can vary facts and details, especially when they relate to things the individual may not want to believe. As a result, scientific reasons that could alter someone’s memory should be considered when assessing the correctness of a witness testimony.

Although Gestmin and Wirecard more recently placed a greater emphasis on contemporaneous documents, Lord Justice Popplewell went further, suggesting that recollection has become undervalued, and that human memory is remarkably accurate. He added “for every honest but mistaken recollection which is rejected by the court, there will be…accurate recollection(s) which the court accepts.”^[3]

^[1] [2013] EWCA 3560 (Comm), para.16

^[2] [2024] EWHC 2534 (Comm), para.285.

^[3] Speech by Lord Justice Popplewell – Judging Truth from Memory: The Scient, para.7.

‍