Mr Griffiths, the claimant, had suffered from serious gastrointestinal illness while on a package holiday in Turkey, and brought a personal injury claim against TUI, the holiday operator.  At trial, Griffiths adduced expert evidence in the form of a report from a microbiologist, which stated that – on the balance of probabilities – the claimant had consumed contaminated food or fluids from the hotel which had caused his illness. This was the only evidence that went to the issue of causation.  TUI went to trial without adducing any expert evidence of its own – choosing not to serve a report – and did not cross-examine the claimant’s expert during the hearing.  However, TUI’s counsel did challenge the report in closing submissions, stating that the claimant’s microbiologist had failed to substantiate his conclusion that the claimant’s illness was caused by eating hotel food, and therefore that his conclusion could not be relied upon and the claimant had not proved his case. Despite the claimant’s expert evidence being uncontroverted prior to closing submissions, the trial judge agreed with TUI’s criticisms of the report, holding that Mr Griffiths had not proved his case and, accordingly, dismissed the claim.

Griffiths appealed to the High Court, where his appeal was allowed on the basis that the evidence had not been challenged by TUI, and therefore that the judge was obliged to accept the expert’s opinion, provided that it complied with the minimum standards set out in the CPR.

TUI then appealed to the Court of Appeal, where the majority overturned the decision of the High Court, noting that there was no strict rule preventing the court from evaluating uncontroverted expert evidence, and that there was therefore nothing inherently unfair in challenging expert evidence in closing submissions only.

Griffiths appealed to the Supreme Court.  It was held that (i) Griffiths had established his case and (ii) a trial judge cannot decide that a claimant has not proven their case, where the evidence provided by the claimant’s expert on a central issue in the case has not been challenged by the defendant in cross-examination.

The TUI case thus shines a light on the concept of “fairness” at trial.  Generally speaking, the judge’s role is to assess evidence for its adequacy and persuasiveness, but she or he must also ensure that proceedings are fair. Fundamental to the fairness of the adversarial system of law upheld by the courts of England and Wales is the general rule that if one party wishes to submit to the court that the evidence of the opposing party’s witness should not be accepted, they are first required to cross-examine that witness. This rule intends not only to preserve the fairness of the trial overall, but fairness to the opposing party and to the witness themselves.  In other words, a party cannot wait until closing submissions to assert for the first time that a witness’s testimony should be rejected, without having ever put those criticisms to the witness during the evidence-giving process.

Accordingly, and consistent with established practice, if a party seeks to ask the judge to disbelieve the evidence of a witness, that witnesses must be given an opportunity to respond, elaborate and/or explain.  In doing so, the judge will have an opportunity to assess the witness’ credibility and attain greater clarity on their opinion.  This rule – which is often referred to as the rule in Browne v Dunn (1893) 6 R. 67 – should not be confined to witnesses of fact, where the witness’s honesty is being questioned, as it is presumed expert witnesses have a strong professional interest in maintaining their reputation from challenges of inaccuracy, inadequacy or integrity.

The Supreme Court’s judgment in TUI does not intend to place the trial judge in a “straitjacket” by dictating what evidence must be accepted or rejected.  The Supreme Court calls for a nuanced approach and flexible application, in order to maintain the overall fairness of the trial.  Giving the only  judgment, Hodge LJ outlined various circumstances where the rule in Browne v Dunn may not apply, which included situations:

1. where it would be disproportionate to cross-examine at length, for example if the judge has set a limit on the time for cross-examination;
2. where the challenge to the witness’s evidence is collateral or insignificant, and the witness does not require an opportunity to respond;
3. where cross-examination would make no difference (i.e. if evidence of fact is “manifestly incredible”);
4. where the expert makes a bold assertion of opinion unsupported by any reasoning;
5. where there is an obvious mistake in the expert’s report;
6. where the expert refuses to respond to criticism or to clarify their report; and/or
7. where the evidence does not comply with the requirements of the CPR.

Key Take-Aways:

The TUI decision will have far reaching consequences, that extend beyond personal injury cases, as it has at its heart the question of procedural fairness.  It may bring an end to this particular form of ‘litigation by ambush’ – where deficiencies in evidence are saved up and only challenged in closing submissions, denying both the relevant witness the opportunity to reply to criticisms of their evidence and the judge from assessing the credibility of the witness’s responses.

In future, therefore, it will be vitally important to ensure that any factual or expert witness evidence pertaining to a central issue is challenged by a party during cross-examination.  That being said, the Supreme Court was at pains to emphasise that this rule is to be applied flexibly, and should not lead to disproportionate expense and cross-examination.

Authored by Alex Sciannaca, Maeve Rowley-O’Donnell, and Emma Childs.