Assessing Witness Credibility: Professional Discipline and Beyond

Published: 08/03/2021 | News

For those that potentially missed it last summer (which, let’s face it, was easily done), the case of R (Dutta) v GMC [2020] EWHC 1974 (Admin) contains an extremely useful summary of the modern guidance and caselaw surrounding the issue of assessing a witness’ credibility and provides a stern reminder to all, not just to professional disciplinary tribunals, that demeanour is not everything, in fact far from it.

Dr Dutta was a cosmetic surgeon. He faced a number of allegations, one group of which related to Patient A. It was alleged that he inappropriately pressurised Patient A into undergoing breast augmentation surgery by offering her a time-limited discount, for financial gain. He was also accused of having failed to obtain adequate informed consent to the surgery and falsely told her that he would not be using PIP implants.

Dr Dutta denied the allegations and relied on some contemporaneous records to support his account. Patient A was cross-examined by reference to the documents which she simply dismissed as fabrications. It was not the GMC’s case that any of the documents had been fabricated or tampered with and therefore their authenticity was not in dispute between the parties.

The allegation in respect of offering a discount for the surgery was found proven by the tribunal and this decision was subsequently appealed. Despite recognising the high threshold to be crossed when appealing findings of fact, Mr Justice Warby found himself “compelled” to accept the appellant’s critique of the tribunal’s decision and reject their approach as “wrong in principle and untenable, for a number/host of reasons”.

He went on to state at paragraph 38 that “I regret to say, in my judgment the Tribunal’s reasoning process is vitiated by at least three fundamental errors of approach. First, the Tribunal approached the resolution of the central factual dispute by starting with an assessment of the credibility of a witness’s uncorroborated evidence about events ten years earlier, only then going on to consider the significance of unchallenged contemporary documents. Secondly, the Tribunal’s assessment of the witness’s credibility was based largely if not exclusively on her demeanour when giving evidence. Thirdly, the way the Tribunal tested the witness evidence against the documents involved a mistaken approach to the burden of proof and the standard of proof.

At paragraph 39 the Judge set out in detail the legal principles involved, as derived from recent caselaw. I make no apology for setting out these paragraphs in full as they represent in my view essential reading and different parts may apply to a case depending on the issues at hand:

  1. There is now a considerable body of authority setting out the lessons of experience and of science in relation to the judicial determination of facts. Recent first instance authorities include Gestmin SGPS SA v Credit Suisse (UK) Ltd [2013] EWHC 3650 (Comm) (Leggatt J, as he then was) and two decisions of Mostyn J: Lachaux v Lachaux [2017] EWHC 385 (Fam) [2017] 4 WLR 57 and Carmarthenshire County Council v Y [2017] EWFC 36 [2017] 4 WLR 136. Key aspects of this learning were distilled by Stewart J in Kimathi v Foreign and Commonwealth Office [2018] EWHC 2066 (QB) [96]: 

“i) Gestmin

  • We believe memories to be more faithful than they are. Two common errors are to suppose (1) that the stronger and more vivid the recollection, the more likely it is to be accurate; (2) the more confident another person is in their recollection, the more likely it is to be accurate.
  • Memories are fluid and malleable, being constantly rewritten whenever they are retrieved. This is even true of “flash bulb” memories (a misleading term), i.e. memories of experiencing or learning of a particularly shocking or traumatic event. 
  • Events can come to be recalled as memories which did not happen at all or which happened to somebody else. 
  • The process of civil litigation itself subjects the memories of witnesses to powerful biases. 
  • Considerable interference with memory is introduced in civil litigation by the procedure of preparing for trial. Statements are often taken a long time after relevant events and drafted by a lawyer who is conscious of the significance for the issues in the case of what the witness does or does not say. 
  • The best approach from a judge is to base factual findings on inferences drawn from documentary evidence and known or probable facts. “This does not mean that oral testimony serves no useful purpose… But its value lies largely… in the opportunity which cross-examination affords to subject the documentary record to critical scrutiny and to gauge the personality, motivations and working practices of a witness, rather than in testimony of what the witness recalls of particular conversations and events. Above all, it is important to avoid the fallacy of supposing that, because a witness has confidence in his or her recollection and is honest, evidence based on that recollection provides any reliable guide to the truth”. 

ii) Lachaux

  • Mostyn J cited extensively from Gestmin and referred to two passages in earlier authorities.45 I extract from those citations, and from Mostyn J’s judgment, the following: 
  • “Witnesses, especially those who are emotional, who think they are morally in the right, tend very easily and unconsciously to conjure up a legal right that did not exist. It is a truism, often used in accident cases, that with every day that passes the memory becomes fainter and the imagination becomes more active. For that reason, a witness, however honest, rarely persuades a judge that his present recollection is preferable to that which was taken down in writing immediately after the incident occurred. Therefore, contemporary documents are always of the utmost importance…” 
  • “…I have found it essential in cases of fraud, when considering the credibility of witnesses, always to test their veracity by reference to the objective fact proved independently of their testimony, in particular by reference to the documents in the case, and also to pay particular regard to their motives and to the overall probabilities…”
  • Mostyn J said of the latter quotation, “these wise words are surely of general application and are not confined to fraud cases… it is certainly often difficult to tell whether a witness is telling the truth and I agree with the view of Bingham J that the demeanour of a witness is not a reliable pointer to his or her honesty.”

iii) Carmarthenshire County Council

  • The general rule is that oral evidence given under cross-examination is the gold standard because it reflects the long-established common law consensus that the best way of assessing the reliability of evidence is by confronting the witness.
  • However, oral evidence under cross-examination is far from the be all and end all of forensic proof. Referring to paragraph 22 of Gestmin, Mostyn J said: “…this approach applies equally to all fact-finding exercises, especially where the facts in issue are in the distant past. This approach does not dilute the importance that the law places on cross-examination as a vital component of due process, but it does place it in its correct context.

45 The dissenting speech of Lord Pearce in Onassis and Calogeropoulos v Vergottis [1968] 2 Lloyd’s Rep 403, 431; Robert Goff LJ in Armagas Ltd v Mundogas SA [1985] 1 Lloyd’s Rep 1, 57.”

  1. This is not all new thinking, as the dates of the cases cited in the footnote make clear. Armagas v Mundogas, otherwise known as The Ocean Frost, has been routinely cited over the past 35 years. Lord Bingham’s paper on “The Judge as Juror” (Chapter 1 of The Business of Judging) is also familiar to many. Of the five methods of appraising a witness’s evidence, he identified the primary method as analysing the consistency of the evidence with what is agreed or clearly shown by other evidence to have occurred. The witness’s demeanour was listed last, and least of all. 

The Judge went on to find that, instead of starting with the objective facts as shown by authentic contemporaneous documents, independent of the witness, and using oral evidence as a means of subjecting these to ‘critical scrutiny’, the tribunal had taken the opposite approach, starting with Patient A’s evidence. It was an error of principle to first ask “do we believe her?” before considering the documents.

Further, the tribunal had placed too great a reliance on Patient A’s demeanour. The Judge pointed out that the tribunal’s reasons did not clearly or sufficiently acknowledge the fluidity of memory, or the fact that an honest witness can construct an entirely false ‘memory’. The fallacy that confident evidence from an honest witness is accurate evidence was starkly illustrated by Patient A’s insistence that the authentic documents shown to her in cross-examination must have been faked. It was plain that her only basis for saying so was that the documents were at odds with what she was saying. She was seeking to ‘explain away’ the problem in a way that maintained her belief in her own account, a classic symptom of cognitive dissonance. 

Finally, the tribunal’s third error when deciding what to make of the apparent mismatch between its impressionistic assessment of Patient A and the contemporaneous documents, was to ask itself whether the documentation was ‘determinative’, and such as to ‘preclude’ the case theory which the tribunal had come to adopt. This was, in effect, to require Dr Dutta to establish to the criminal standard a defence to the charge. Whereas the tribunal’s proper task was to assess the evidence in the round and decide whether the GMC had discharged the burden of showing that it was more likely than not that pressure was applied by means of a discount offer, for financial motives, as alleged.

For these reasons the Judge found that the tribunal’s factual determination on the charges could not stand and that the only reasonable conclusion available on the evidence was that Patient A’s recollection that she had been offered a discount to have the surgery quickly was not reliable, and the GMC’s case was not proven.

It is John Brown‘s view that this case provides a useful review of the modern principles to be applied by any fact finder when evaluating the evidence presented by a witness and has general application far beyond professional disciplinary proceedings. It is therefore to be remembered, and perhaps (gently) reiterated to the tribunal in an appropriate case, that reliance on a witness’s confident demeanour is now very much a discredited method of judicial decision-making.

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