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Case analysis: Robinson v Liverpool University Hospitals NHS Trust and Mercier [2023] EWHC 21 (KB)

Case analysis

Robinson v Liverpool University Hospitals NHS Trust and Mercier [2023] EWHC 21 (KB)

Prepared by Nadia Whittaker, Counsel for Mr Mercier

Miss Robinson’s claim and the trial

Miss Robinson, a long standing dental phobic, was referred to St Helens & Knowsley Hospital NHS Trust for extraction of 3 teeth (UL7, LL7 and LR7) in or around September 2015. She was not seen until June 2016 when it was noted that the tooth that had been in a position of UL7 had been previously extracted, and an attempt made to undertake extraction of only 2 teeth (LL7 and LR7) under sedation in August 2016. Miss Robinson was too nervous for this to be completed and was referred to the Defendant Trust for the procedure to be undertaken under general anaesthetic. Nevertheless, on 8 November 2016, Mr Bajwa, a Trainee in Oral and Maxillofacial Surgery, obtained her consent for extraction of 3 teeth (UL7, LL7 and LR7), and Miss Robinson signed a consent form to this effect before general anaesthetic was administered. It subsequently transpired that Mr Bajwa was looking at an old x-ray, which showed two molar teeth in the upper left quadrant whereas by November 2016 Miss Robinson only had one tooth remaining there.

When Mr Bajwa examined Miss Robinson in theatre, he began to have doubts as to whether the only tooth remaining in the upper left quadrant should be extracted as he did not find it to be as grossly carious as the referral described it. In his evidence, Mr Bajwa indicated that he became concerned about “the possibility of ‘wrong site surgery’” and made the decision in “the patient’s best interests” to leave that tooth in situ.

When Miss Robinson woke up, she was taken aback that only 2 of 3 teeth were removed. She asked Mr Bajwa about it, and he informed her that he had been looking at the wrong x-ray when he took her consent. As far as Miss Robinson was concerned, the tooth that remained was causing her pain and she expected it to be removed. Mr Bajwa told her that there was nothing further than he could do for her. Miss Robinson was distressed by this outcome and felt that this increased her dental phobia, such that she could not face any further dental treatment despite experiencing pain at UL7. This was genesis of her personal injury claim.

Mr Mercier graduated in 1996 from Manchester University as a Bachelor of Dental Surgery. Since 2000 he was a member of the Faculty of General Dental Practitioners at The Royal College of Surgeons. In 2010 he completed a master’s degree in Dental Implantology at Warwick University. From 2008, he has been the principal dentist at his own dental practice. He was instructed by Miss Robinson’s solicitors, Liver Law, to examine her on 4 May 2018 and prepare a medico-legal report.

In his report dated 16 May 2018, he reported that Miss Robinson described to him the index events as follows:

“Claimant attended for teeth to be removed on 08.11.2016 and the treating dentist reviewed an old X-Ray and failed to remove the correctly identified teeth for treatment and removal, leaving the damaged tooth and causing the need for the Claimant to attend again for the damage tooth to be removed which has caused increase in pain and suffering and also the Claimant has a severe phobia of the denist (sic)”

There was no section on breach of duty in Mr Mercier’s original report, although reference was made to “errors” in the treatment afforded to her by the Defendant Trust. Mr Mercier’s report was served with the Particulars of Claim alongside a report from a clinical psychologist. The allegations advanced by Miss Robinson’s in the Particulars of Claim focused on a failure to review her records, take proper account of the consent form she signed and failing to remove UL7.

Subsequently, Liver Law asked Mr Mercier to prepare a liability report, which he did by adding a section on breach of duty to his original report. In this section he stated, “the clinical records and history provided by Miss Robinson indicate that the oral surgeon who carried out the treatment did not adequately assess Miss Robinson either clinically or check the previous referral notes and radiographs satisfactorily in order to confirm which teeth were planned for removal”.

Although a failure to examine Miss Robinson was not advanced as a specific allegation in the Particulars of Claim, in the Reply to the Amended Defence, it was pleaded that the lack of examination prior to taking her consent meant that there was a failure to obtain her informed consent.

The Court gave permission to Miss Robinson to rely on the evidence of Mr Mercier who was described in the Court directions as a “Dentist”. The Trust was given permission to rely on the evidence of Mr Webster described as “Consultant Maxillofacial Surgeon”. The discrepancy between the experts’ respective specialities was not raised by the parties or the Court at the directions stage.

Mr Mercier and Mr Webster prepared a joint statement in which they reached a measure of agreement, including on the following issue:

“There is no evidence in the clinical records that an examination was, or, was not, carried out by the treating clinicians prior to the consent being completed.

Both experts agree that a reasonable body of practitioners would carry out and record the results of an examination prior to the consent being completed.”

Mr Bajwa in his witness statement did not address the issue of examination of Miss Robinson prior to taking her consent. At the trial before Recorder Hudson, he was cross-examined on this point, particularly, as to how he could have missed the discrepancy between the presence of 2 molars in the upper left quadrant on the x-ray versus only 1 molar in Miss Robinson’s mouth. He accepted that he made a mistake and that this happened before taking Miss Robinson’s consent.

One would have expected this evidence combined with the agreed expert evidence regarding the requirement for an examination to have set the scene for the contention pursued by Miss Robinson in the Reply that there was a failure to take her informed consent. However, on the first day of the trial, a discussion had taken place between Recorder Hudson and Miss Robinson’s Counsel, Mr Gray, in which it was agreed that the central issue in the case was whether or not a reasonable body of dental surgeons would have concluded, during the course of the surgery, that the tooth was restorable based on the information that Mr Bajwa had.

Given how the issue for the Court was defined in the opening by Miss Robinson’s Counsel, the spotlight shifted away from the actions on Mr Bajwa at the time of taking Miss Robinson’s consent and onto his actions in theatre. The Defendant’s Counsel, Mr Maddison, went on to cross-examine Mr Mercier about his experience of extracting teeth under general anaesthesia and established that the last time he undertook such extraction was in 2000. Mr Mercier was then cross-examined in some detail about Mr Bajwa’s decision-making process in theatre and reasonably conceded that in the situation in which Mr Bajwa found himself it was not unreasonable to err on the side of caution and leave the tooth in situ. Indeed, Mr Mercier acknowledged that decisions about surgery were not within his expertise. In light of this and the manner in which the central issue was defined, Mr Mercier’s attempts to stress in his evidence that, had Mr Bajwa examined Miss Robinson property, he would never have found himself in this situation in the first place, appeared to fall on deaf ears.

At the conclusion of Mr Mercier’s evidence, Counsel for Miss Robinson asked for an adjournment following which he informed the Court that the case was discontinued. Counsel for the Defendant Trust then asked the Court for permission to make an application to join Mr Mercier as a party for the purposes of a TPCO.

The Defendant’s application for a TPCO

The Defendant’s application against Mr Mercier was premised on the contention that he was simply the wrong expert to give expert evidence and should have appreciated this point, either at the outset or during the course of litigation. The Trust argued, “…it would, and should, have been obvious to Dr Mercier that as a General Dental Practitioner, he should not have been expressing an expert opinion on the standard of care afforded to the Claimant by a Maxillofacial Surgeon.”  The Recorder approached the application for a TPCO on this basis, defining the issue that she had to decide on the application as follows:

“The application before me is predicated on the specific assertion that it should have been obvious to Dr. Mercier at the outset, and at various stages throughout the proceedings, that he was not the appropriate expert to opine on the management, and treatment afforded to the Claimant on 8thNovember 2016. In the circumstances of this application therefore I confine myself to the nature of Dr. Mercier’s expertise.”

The Recorder decided that Mr Mercier was lacking expertise to act as a medico-legal expert in a case involving care provided by a Maxillofacial Surgeon. In her view, Mr Mercier should have refused to act as a medico-legal expert for Miss Robinson at the outset and, had he done so, she “could not have pursued a claim in dental negligence”. On the issue of causation, the Recorder found it was “inconceivable that an alternate expert would have come to the same conclusion” as Mr Mercier did. This was the foundation for the Recorder’s decision that Mr Mercier should be liable for the entire sum in which the Defendant’s cost budget had been assessed; in other words, for its total outlay in defending the case from the outset.

The decision on appeal

Relevance of the expert’s qualifications

Having highlighted that the basis of the application for a TPCO was the inappropriate nature of his expertise, Sweeting J went on to carefully examine from [41] onwards “Whether the fact that Mr Mercier was not a maxillofacial surgeon disqualified him from giving expert evidence” in this case. He identified the following relevant considerations:

  1. Mr Webster was qualified as a dentist as was Mr Bajwa. Mr Webster had gone on to qualify as a maxillofacial surgeon and Mr Bajwa was in the course of doing so.
  2. Miss Robinson was having an extraction under general anaesthesia because of her morbid fear of dental procedures. Mr Bajwa agreed in his evidence that if not for this phobia her extraction would have been carried out by a general dental practitioner. Mr Webster’s evidence in his report was to the same effect. A number of Miss Robinson’s extractions had been carried out by general dental practitioners.
  3. There was no suggestion that it was not within the competence and scope of the clinical practice of a general practitioner dentist to carry out extractions and to take and report on x-rays for that purpose.
  4. The ability of a general dental practitioner to assess the viability of a tooth and to determine whether it required extraction was also not in issue. The referrals had been made by general dental practitioners because they assess teeth as unrestorable.
  5. It follows that Mr Mercier did not need to be a maxillofacial surgeon to express an opinion on these topics.
  6. The experts identified a failure to record a pre-operative examination as falling below the standard to be expected of a reasonable body of “practitioners”. They also agreed that an examination was required prior to an extraction. They did not draw any distinction for this purpose between an extraction performed by a general dental practitioner under local anaesthetic or a surgical extraction under general anaesthetic. The purpose of the examination was limited, but important, and was, amongst other things, to check which tooth required extraction. Although there was questioning at trial directed to the facilities available at the hospital to carry out a full examination there was no suggestion from the experts that the examination they were referring to could not have been carried out by Mr Bajwa when he saw Miss Robinson, or on Mr Webster’s part, that any different standard applied to an examination by him as opposed to a general dentist performing an examination prior to an extraction.


Sweeting J felt it “instructive to consider what an examination would have demonstrated if it had been recorded”. He went on to say:

  1. … Had the x-ray in fact conformed to what was in the patient’s mouth then it seems implicit in [Mr Bajwa’s] evidence that he may have extracted a tooth in the position of UL7. His assessment of the state of the single tooth that he found appears to be a consequence of the fact that he concluded that UL7 was not present. In any event and against the background of this evidence the train of events would arguably have been very different if Mr Bajwa had discovered that the x-ray was not accurate prior to operating.
  2. The records indicate that Mr Bajwa identified the tooth during surgery as UL6. This was itself wrong; as the experts agreed the only upper left molar present was UL7.
  3. The post-operative recovery notes indicate that the explanation given to Miss Robinson was that UL7 had already been removed (again this is incorrect).
  4. It can have been no part of Mr Bajwa’s thinking that there had been a referral in respect of the lower molars alone because, as the judge commented, he did not have that referral.

Relevance of the law on consent

The Recorder criticised Mr Mercier because he, as she put it, “for some unfathomable reason concludes that Mr. Bajwa should have accepted the unsupportable consent form of the 8thNovember 2016 which he is said to have created without proper review or examination”. Sweeting J observed:

  1. This was of course the consent form which Mr Bajwa himself completed. Whatever the confusion about documents, he had taken consent for the removal of a tooth in the Upper Left Quadrant. There was only one tooth in that location which he identified on the consent form as the “upper left second molar”, presumably on the basis of what was shown on the x-ray. The test for informed consent following Montgomery v Lanarkshire Health Board [2015] UKSC 11 is that a doctor is under a duty to take reasonable care to ensure that the patient is made aware of any material risks involved in treatment and of any reasonable alternative or variant treatments. On Mr Mercier’s evidence the failure to properly assess and examine fed into the consent process with the result that the issue of whether to remove the tooth had to be confronted intra-operatively rather than with the patient in the course of obtaining her consent.

Sweeting J then added:

  1. … By the time Mr Bajwa was in surgery the information that he had available to him was limited and could not include any discussion with Miss Robinson about whether or not she was in pain from the tooth or why the x-ray provided to him was inaccurate. It might not have proved possible to resolve matters on the day but Miss Robinson’s operation had already been postponed on the previous day and she would have been in a position to choose whether to go ahead with the removal of the lower teeth only or wait for a further operation in which, if necessary, the upper molar could be removed at the same time. There was psychological evidence about the effect on her mental health of dental treatment.
  2. The out-of-date x-ray which Mr Bajwa looked at prior to the operation showed two upper left molars. When he operated and saw only one he was on the horns of a dilemma. He had a patient under general anaesthetic to whom he could not talk. He chose not to extract given the uncertainty at that stage as to which tooth was present and the appearance of the tooth.
  3. Mr Mercier’s opinion was, in effect, that this was a dilemma of his own making because he had failed to carry out a proper examination prior to the operation to identify that there was only one tooth left rather than the two shown on the x-ray, or he had simply not looked properly at the x-ray. Had he done so then that would necessarily have prompted further investigation and a conversation with the patient as part of the consent process. The judge took the view that the breach of duty in failing to carry out an examination on the day of the extraction had not been pleaded. Whether that is right or not such a breach had been identified by Mr Mercier in his report.
  4. Though the surgeon could hardly be held responsible for the errors and omissions in the documentation which had been forwarded to him, the lack of a proper and documented clinical examination was the central failing identified by Mr Mercier in his expert report. He did not give a view as to what a surgeon should have done in the circumstances that confronted him during the operation; his opinion was that this state of affairs should not have arisen in the first place.
  5. Whatever the basis for the earlier referrals, Miss Robinson expected to have three teeth removed, including her remaining and painful upper left molar. She consented to that procedure. The contemporaneous documents supported her case. She immediately queried why all three teeth had not been extracted when she came round after her operation. That remained her position at trial. She said that the molar was causing pain and that she had asked whether it could be removed at the same time as the lower molars. According to the expert joint report, where the records were reviewed, she had attended a day case assessment on 25 October 2016 when extraction of all three teeth had been recommended. She contacted her NHS dental practice the day after the operation to complain that the upper molar had not been removed.
  6. Had the discrepancy been raised with Miss Robinson at the consent stage she would it appears, on her evidence, have asked for the tooth to be removed, given the pain it was causing her. She understood this was to be the procedure carried out during the operation to which she had consented.

Misplaced criticism of an examination 18 months after the event

The Recorder also criticised Mr Mercier for preparing a report based on examination of Miss Robinson some 18 months after the surgery on 8 November 2016. Sweeting J observed at [61] that “Although Mr Mercier was criticised by the judge for his approach to assessing the viability of the tooth, Mr Webster had taken the same course, as is implicit in the judge’s comment at paragraph 6 of her judgment”.

Furthermore, Sweeting J noted that, although Mr Mercier’s report was prepared before he received the radiographs from 2015, it was based upon his own clinical examination of Miss Robinson. He noted at [62] “Whether the interval of 18 months between the operation and that examination invalidated his opinion was undoubtedly a matter which could be explored in the evidence”: however, in his view the Recorder “went much further saying that any allegation of negligence based on the examination demonstrated a flagrant, reckless disregard of his duty to the court”. Sweeting J held that Mr Mercier had been asked to comment on causation and considering the viability of the tooth was “a necessary part of the case”. He added at [63], “Whether a tooth could be restored was clearly a matter on which Mr Mercier was able to give an opinion. He could only do so on the basis of his own examination of the claimant and the x-rays.

Sweeting J’s conclusion

  1. Mr Mercier was asked to identify breaches of duty. He was not specifically directed to failures in the conduct of the operation itself. He identified a breach of duty in relation to the clinical examination as part of the consent process prior to the extraction. There was nothing illogical or (as the judge appeared to suggest) partisan about his conclusions. They were supported, in part at least, by the Respondent’s expert. Mr Bajwa acknowledged an error on his part. If the extraction had then been performed by a general dental practitioner the challenge to his standing to express an expert opinion on these matters would fall away. Both experts and Mr Bajwa were dentists. In the circumstances of this case there could be no sensible suggestion that any different standard applied to the examination of the patient’s teeth and the x-rays to confirm which required extraction as between a surgeon dentist and a general practitioner.
  2. A failure to carry out a proper examination had an arguable consequence in relation to consent if, absent the error, it would have led to a discussion with the patient in relation to the scope of the extraction procedure she was about to have.
  3. Mr Mercier was qualified to give an opinion in relation to the viability of a tooth and whether its condition was such that it required extraction. Both he and Mr Webster gave their opinions on the point given that it went directly to causation.
  4. For these reasons the judge was wrong, in my view, to conclude that Mr Mercier had stepped outside the boundary of his expertise in giving his opinion about breach of duty and causation in relation to the examination carried out prior to extraction or the viability of the tooth which Miss Robinson expected to be removed but which was not. There may well have been grounds to criticise Mr Mercier’s performance as an expert witness and to attack his conclusions, but this was not an exceptional case and did not involve a flagrant or reckless disregard of an expert’s duty to the court. On the facts of this case it would not be just to make a costs order against him in any amount. The appeal is therefore allowed.

Key messages from the judgment

  • The test for a TPCO as set out at [93]-[96] of the judgment of Mr Justice Peter Smith in Phillips v Symes [2004] EWHC 2330 represents a high threshold. It is necessary to establish that the expert acted in flagrant reckless disregard of his duties to the Court”.
  • The scope of the suitability of an expert’s expertise is to be judged with reference to the issues at stake and not with reference to the title of or post occupied by the treating clinician.
  • It is inappropriate to criticise the expert for seeking to formulate his expert opinion on the basis of his own findings at the time of the medico-legal examination, which inevitably takes place some time after the index events.
  • The terms of section 51 of the Senior Courts Act 1981 expressly require proof of causation (see Travelers Insurance Company Ltd v XYZ [2019] UKSC 48 per Lord Briggs JSC at [80]).
  • The importance of the doctrine of informed consent as set out in Montgomery v Lanarkshire Health Board [2015] UKSC 11 should not be overlooked when considering causation. An argument that the clinician did the “right thing” by taking a decision in the patient’s best interests when she was under general anaesthesia is not a substitute for proper consideration of the issue of causation that flows from a potential failure to obtain the patient’s informed consent.
  • The Defendants should not be lulled into a false sense of security about their prospects of success on an application for a TPCO merely because the Claimant’s legal representatives choose to discontinue the case following the conclusion of the Claimant’s expert evidence. The role of the legal representatives cannot be ignored. It is for them to put forward the Claimant’s case and to ensure that it is pleaded and argued in accordance with the expert evidence obtained.


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