In this blog post, Cressida Mawdesley-Thomas considers the recent case of Griffiths v TUI UK Limited [2020] EWHC 2268 (QB).

It is difficult to overstate the impact of this ruling in relation to the way in which package holiday food poisoning cases have generally been fought since the key Court of Appeal decision in Wood & Anor v TUI Travel Plc (t/a First Choice) [2017] EWCA Civ 11 (discussed in detail here).

In summary, Martin Spencer J held that it was not open to a defendant to invite the trial judge to disregard a claimant’s expert report where it represented the only expert evidence on the issue of causation. Provided that the report met the minimum requirements of CPR 35PD 3, the court was in effect bound to accept the expert’s conclusions – even if the reasoning was demonstrably poor.

At the conclusion of this blog post, we explain our understanding of the likely implications for future litigation.


A claim was brought by Mr Griffiths against TUI for breach of contract in relation to gastric illness suffered whilst on an all-inclusive holiday in Turkey in August 2014. Mr Griffiths and his wife gave the only oral evidence.

Mr Griffiths relied on expert reports from a gastroenterologist (concerning condition and prognosis) and from a microbiologist (concerning causation). TUI was given permission to obtain its own microbiology evidence in reply, but declined to do so (until it was too late, and permission for the late evidence was refused). Importantly, the microbiologist had access to stool samples, which identified contamination with a number of pathogens.

At first instance HHJ Truman accepted in full Mr Griffiths’ evidence of his illness. However, the claim still failed as the learned judge rejected the expert evidence from the microbiologist on the basis that the reasoning in the report was deficient:

I am not satisfied that the medical evidence shows, following Wood v TUI, that it is more likely than not that the claimant’s illness was caused by ingesting contaminated food or drink supplied by the hotel. I accept counsel for the defendant’s submissions that a number of the assertions made are bare ipse dixit. There is sometimes a huge gap in reasoning between undoubted factual matters (such as incubation periods) and the conclusion that the hotel was at fault…

Mr Griffiths appealed. It was argued that the judge had not been entitled to reject the expert’s report on this basis. The appeal succeeded.


HHJ Truman had accepted TUI’s submission that the correct approach to causation in food poisoning cases was set out in the obiter comments of the Court of Appeal in Wood, which indicated that the discounting of other possible sources of infection and proof of a wider outbreak of illness may be necessary.

See, for example, Sir Brian Leveson at [34]:

I agree that it will always be difficult (indeed, very difficult) to prove that an illness is a consequence of food or drink which was not of a satisfactory quality, unless there is cogent evidence that others have been similarly affected and alternative explanations would have to be excluded.

However, in Griffiths, Martin Spencer J said of this passage at [15]:

I would comment that it seems unlikely that Sir Brian Leveson P had in mind a case such as the present where the Claimant has been admitted to hospital, has provided stool samples, those samples have been analysed and shown to contain certain pathogens and those pathogens have then been considered by an expert microbiologist in the process of an investigation into causation by the Claimant’s solicitors. Those words are, though, particularly apt where a person has suffered gastroenteritis whilst on an all-inclusive holiday and relies on that alone as proving causation: that would not be enough in the absence of evidence of an “outbreak”, that is others being similarly affected in such numbers as to lead to the conclusion, on the balance of probabilities that the food or drink supplied by the hotel was to blame.

Martin Spencer J went on endorse a distinction between “quantitative” cases, “where the Claimant was seeking to prove his case from the mere fact of illness”, and “qualitative” cases, “where stool samples gave evidence of the potential pathogens at work and expert evidence gave an opinion as to which of those pathogens was the actual culprit, and the most likely source of infection.” In qualitative cases, the absence of evidence of large numbers of other guests similarly affected may be of less significance whilst, in a quantitative case, “such absence of evidence will be fatal to the case’s success.”

This case was a “qualitative” one, because Mr Griffiths had obtained stool samples which formed the basis of an expert report on causation. The judge went on to consider what approach to the expert evidence was required in cases of this type.

In general, he said, where an expert’s opinion is disputed, that opinion will carry little weight if, on proper analysis, the opinion is little more than assertion on the part of the expert. That this is so was made clear by the Supreme Court in Kennedy v Cordia (Services) LLP [2016] 1WLR 597 where Lords Reed and Hodge said at [48]. As Lord Prosser pithily stated in Dingley v Chief Constable, Strathclyde Police 1998 SC 548, 604: “As with judicial or other opinions, what carries weight is the reasoning, not the conclusion.”

However, in Coopers Payen Limited v Southampton Container Terminal Limited [2004] Lloyds Rep 331, 338, Clarke LJ contrasted the position where an expert, for example a single joint expert, is the only witness on a particular topic with the position where the expert’s opinion is only part of the evidence. At [42] he said (emphasis added):

All depends upon the circumstances of the particular case. For example, the joint expert may be the only witness on a particular topic, as for instance where the facts on which he expresses an opinion are agreed. In such circumstances it is difficult to envisage a case in which it would be appropriate to decide this case on the basis that the expert’s opinion was wrong.

In Griffiths at [33], Martin Spencer J applied this passage, saying:

I take the view that a court would always be entitled to reject a report, even where uncontroverted, which was, literally, a bare ipse dixit, for example if Professor Pennington had produced a one sentence report which simply stated: “In my opinion, on the balance of probabilities Peter Griffiths acquired his gastric illnesses following the consumption of contaminated food or fluid from the hotel.” … However, what the court is not entitled to do, where an expert report is uncontroverted, is subject the report to the same kind of analysis and critique as if it was evaluating a controverted or contested report, where it had to decide the weight of the report in order to decide whether it was to be preferred to other, controverting evidence such as an expert on the other side or competing factual evidence. Once a report is truly uncontroverted, that role of the court falls away. All the court needs to do is decide whether the report fulfils certain minimum standards which any expert report must satisfy if it is to be accepted at all.

The minimum standards that he identified were the requirements as to form and content set out in CPR 35PD 3. He doubted whether any report from an expert which substantially complied with CPR 35PD could ever justifiably be characterised as a mere ipse dixit.

Mr Griffiths’ uncontroverted microbiology report did satisfy these minimum requirements and it would therefore stand.


Since Wood, package travel food poisoning claims have generally been defended either on the basis that the factual assertions underlying the expert evidence are not made out or are false (see the discussion in a previous blog post here) or that the reasoning in the expert report is so deficient that, following the exacting approach to causation set out in the Court of Appeal’s comments, it should not be accepted.

Martin Spencer J’s judgment changes things dramatically.

In “qualitative” cases, a single uncontroverted expert report will apparently be enough for a claimant to succeed on causation provided that it complies with the minimum standards set out in CPR 35PD. This places the claimant at an apparent advantage given that the “norm” for expert evidence in food poisoning cases under the pre-action protocol is assumed to be a single report from a GP instructed by the claimant (see our blog post on the protocol here).

Defendants will now be well advised to seek permission for their own expert evidence in these cases or risk the court being bound to accept even poorly-reasoned evidence produced by a single expert instructed by the claimant. The judgment in Griffiths itself will surely be a significant support for such applications, when they are inevitably made. The result in the immediate future will be to increase the costs and complexity of litigating these low-value bulk claims – the very thing that the pre-action protocol was implemented to avoid.

There are apparently limits to this change in approach. Martin Spencer J’s judgment only expressly applies the new approach to “qualitative” cases. That is, cases “where stool samples gave evidence of the potential pathogens at work and expert evidence gave an opinion as to which of those pathogens was the actual culprit, and the most likely source of infection.”

In “quantitative” cases – that is, cases where the expert has had no access to stool samples – “such absence of evidence [of a greater outbreak] will be fatal to the case’s success.” The obiter comments of the Court of Appeal in Wood apparently still stand. In fact, Martin Spencer J’s wording (“will be fatal”) is arguably even harsher than that employed in Wood.

But is this line between qualitative and quantitative cases really so easy to draw? What if the claimant does not have access to stool samples but instructs an expert who still feels able to comment on the potential pathogens at work given the description of the symptoms and their own expert knowledge of relevant background conditions (e.g. the types of bacteria present in the locality and the prevalence of their transmission through food and drink as opposed to alternative sources of illness)?

In the absence of a broader outbreak, could a judge safely reject this evidence as being quantitative rather than qualitative? Would a defendant be well advised to defend the case without their own expert evidence simply on the basis that the expert had no access to actual samples identifying the precise pathogen responsible? We are not so sure. These are just some of the difficult questions raised by this judgment.

We note that the time for permission to appeal to the Court of Appeal has been extended to 21 September 2020. We will report on any further developments as soon as we hear of them. In the meantime, we anticipate a dramatic change in the way these cases are fought and an increased appetite on the claimant side for litigating cases that were previously considered too risky to progress.

James Beeton Cross-Border

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