A powerful critique of the conduct of an expert witness can be found in the judgment of HHJ Richard Clarke in Hertfordshire County Council v Mother & Ors [2022] EWFC 106.  A medical expert was found to have fallen considerably short of their duty to the court.

“When presented with the relevant literature [Professor AM] did a quick about turn and reverted to the previous report. Professor Sellar sought to justify his opinion, during which it became clear he had not read the relevant documents, not fully read the literature which had been provided and had mis-read and misinterpreted the relevant research.”


The local authority brought proceedings alleging that injury to a child was non-accidental.  It relied on medical evidence.  One expert [Professor AM] changed their view during the course of the case.  The next expert, Professor Sellar, maintained the view as to the cause of the injuries.  However it became clear that this Professor had not read all the relevant material. Things did not go well for this expert.


  1. The Local Authority brought these proceedings based on the severity of the injuries and the report of [Dr N]. However, [Dr N] was not the expert authorised by the court. It was therefore somewhat surprising to find Professor Sellar seeking to defer to [Dr N]’s opinion, when struggling to justify his own opinion, when Professor Sellar was the expert called to report in the case and appeared before the court to justify the opinion. [Dr N] understood the mechanism he was dealing with, and therefore the basis of his report, was a typical domestic impact head trauma, akin to a fall from a piece of furniture, a toddler falling over and banging their head on a hard surface or a child being dropped from standing height onto a surface such as a pavement.
  1. At the conclusion of [Professor AM]’s evidence a discussion took place about whether a summary of [Professor AM]’s evidence could be agreed and sent to Professor Sellar before he gave evidence the following day. It was clear it was too complex and there was insufficient time for this to be achieved. In the circumstances the information provided to Professor Sellar about the change of position was limited. However, while he started evidence on 23 March 2022 it then continued into 24 March 2022. If he wished to consider the documentation further and reconsider his opinion between the 2 occasions he could have done so and he did not.
  1. There was limited subtlety in the cross-examination of Professor Sellar, which should not be read as a criticism of counsel in any way. At the time he went into the witness box he knew he was the only expert giving evidence the injury was unlikely to be accidental and that he would be challenged on that. Professor Sellar was specifically taken through his duty to the court, his certification in his report and what the parents said were breaches of his duty and deficiencies in his evidence.
  1. An expert has a duty to the court and to the parties. It was clear from Professor Sellar’s evidence that he had not fully or properly considered the papers sent to him. While he felt “There is an error on opening the GOSH file” made it “clear as day” that he had not read the GOSH records, that was not clear to the parties, or the court, prior to his evidence. While no party sought to clarify this with him prior to his attendance at court, an error implies a problem or a mistake. It is wholly different from “I was unable to open the GOSH file”.
  1. When the court authorises expert evidence it is based on an estimate of fees, and when the work can be done by, following enquiries made with the expert or their office. The Legal Aid Agency will only authorise a limited number of hours, and therefore limited cost, for an expert to prepare their report. For the type of report provided by Professor Sellar the standard limit is 10 hours. Professor Sellar estimated 45 hours and he was instructed on this basis, with the solicitor confirming prior authority had been sought for this. He was asked, in the letter of instruction, to identify if his fees were likely to exceed the 45 hours. There was no evidence before the court that he ever did so. If he was unable to do the work in the time due to lack of authorised hours he was under a duty to seek an increase. If he was unable to do the work due to workload he should not have accepted the work or committed to completing it in the time allowed.
  1. The court is informed Professor Sellar charged for the full 45 hours. Upon behalf of Father it was identified that, if he was unable to open the GOSH records, he considered just over 300 pages of relevant material. His time was broken down as 12 hours for “Preparation, includes reading & review of documentation – medical records, reports and bundle”; 6 hours for reviewing the scans and images, 8 hours for results/formulation, consideration and clinical formulation and an extra 19 hours for report writing (a total of 45 hours). While the report ran to 45 pages, it contained 27 pages plus appendices. Of the 27 pages only 7 pages provided a substantive opinion, there were 2 pages of background and 12 pages of information pulled in from records and literature.
  1. Professor Sellar accepted in evidence that he knew there would have been reports from the scans at GOSH. He knew he was missing reports he had specifically been asked to comment on, yet he provided his report without seeking those reports or specifically stating he had not seen them. This was despite his certification that he had done his best, in preparing the report, to be accurate and complete, and that he had drawn attention to all matters, of which he was aware, which might adversely affect his opinion.
  1. At the time that Professor Sellar reported it is clear there was a range of reasonable opinion that the injuries were accidental. He was dealing with a complex fall, involving gravitational and rotational forces, onto a hard surface. His statement that “The history of a fall from~ 4 -5 feet. This on its own is very unlikely to cause the severe (radiological) brain injury” ignored the complex nature of the fall.
  1. There is an obvious and fundamental difficulty in research data in relation to injuries such as were sustained here. Unless the mechanism of injury was observed independently and accurately then researchers are unaware whether they are dealing with a common occurrence, an “outlier” (a rare but possible occurrence) or an inflicted injury. This applies as much to cases where significant injuries are sustained as when a child sustains little or no significant injury whatsoever, although those circumstances may never be reported and mean statistics are not a fair representation of the true picture. There is also a question of whether research is statistically significant, ie are there sufficient cases for a pattern or range of injuries to be derived/defined. As a result, the research pool of reliable date is very limited. It has been supplemented by experiments on dead babies (Weber) and pigs (Powell). Within the research, there is limited information on how injuries were sustained, when the devil is in the detail. This may be indicative of unclear histories overall.
  1. Professor Sellar made reference to research in his report. He had not considered the main work by Bilo et al. He mis-quoted or mis-interpreted the research of Weber in preparing his report. None of the medical literature rules out the likelihood the injuries were caused as described by the parents.
  1. Both [Professor AM] and Professor Sellar did not identify relevant literature when providing their reports. Professor Sellar’s failure was compounded by not properly considering the documentation he had been sent and not advising his instructing solicitor that he had been unable to access some of the records. If he had read the records properly he would have identified there was a consensus statement from the neuroradiologists at GOSH which he did not have and needed to see.
  1. When presented with the relevant literature [Professor AM] did a quick about turn and reverted to the previous report. Professor Sellar sought to justify his opinion, during which it became clear he had not read the relevant documents, not fully read the literature which had been provided and had mis-read and misinterpreted the relevant research. The characterisation of him mis-representing the report of [Dr N] in the reference to stamping, as sought by Mother, is a step too far in this court’s judgment, but the reference is indicative to a lack of care in preparation of his report. The court, and the parties, were expecting, and entitled, to hear the evidence of Professor Sellar and not to hear the evidence of [Dr N] by proxy.
  1. [Dr TM] and Professor Sellar disagreed over whether there was evidence of trabecular fractures, consistent with a fall. Professor Sellar was aware of the issue, because it was covered in [Dr G]’s letter of [Day 14] as well as him referencing the consensus neuroradiology opinion. They are entitled to disagree, but Professor Sellar was required to set out the range of opinions in his report and did not do so. Professor Sellar accepted they would be consistent with a fall on the head.
  1. Professor Sellar accepted that he and [Professor AM] were equally qualified to comment on fractures to the skull and spine. By the conclusion of the evidence of Professors [O] and Sellar they accepted as a proposition that the energy from impact to the unyielding wood/concrete floor would have nowhere to go but round the inside of the skull and that the consequences were simply unpredictable.
  1. Professor Sellar spoke about the burst nature of the injury. Excluding the burst fracture, all professionals accept a fall from Father’s arms could have caused the injuries. Professor Sellar believed the herniation of the injury had not been considered by [Dr TM] and her colleagues, despite the consensus statement referencing the herniation in 2 separate places.
  1. With a simple drop onto a flat surface you would not expect a piece of the skull to be pushed into the brain and cause the damage that was done. However, this was not a simple drop onto the floor and there were unknown rotational forces in play. Professor Sellar relied on a paper by Ellis which included no description of the circumstances that led to the burst fractures described and was based upon 7 cases, one of which was caused in a road traffic accident, one was a fall from a second storey window and 5 were NAI. The court reminds itself the Ellis paper is an American paper and an American second storey is a British first floor, although it is accepted this point was not put to him.
  1. Professor Sellar identified consideration of the broad canvas of evidence was outside his experience. Mother seeks to criticise that failure. However, that is exactly the reason why there is the court process and the court is required to take into account the broad canvas of evidence. That includes opinions from the perspective of the police, social workers and medical professionals. The issue arises that to expect a medical professional to approach a case from a social work perspective is to attempt to redefine their role in the overall process.
  1. It must also be remembered that the court makes decisions based on the best information available at the time. As previously stated, what may be unexplained today may be perfectly well understood tomorrow. The issue for the court is whether the Local Authority are able to prove their allegations on the balance of probabilities. They are unable to do so, and accept they are unable to do so. That position is also endorsed by the Guardian, who shares the concerns in respect of the expert evidence
  1. The Local Authority accepts that having heard the evidence of Professor Sellar and [Dr G] they:
131.1.    have failed to consider all the evidence that was available to them at the time of their reports and letters;
131.2.    were approaching the questions under a false pretence that the parents accounts were inconsistent and failed to take into account the views of the police and other professionals around the plausibility of their accounts.
131.3.    do not appear to have necessarily reached an independent opinion on the cause of the injuries, with it appearing that Professor Sellar based much of his opinion on the views of [Dr N] and [Dr G], where [Dr G] had, for reasons he was unable to explain, changed his opinion from accidental to non-accidental after speaking with the safeguarding team at GOSH
  1. The Father described Professor Sellar as an expert who, as the court accepts was evidenced by Professor Sellar himself:
132.1.    does not read the material provided
132.2.    does not make it crystal clear to his instructing solicitor that he has been unable to access crucial material
132.3.    does not follow the terms of his letter of instruction
132.4.    relies on summaries and/or views of others without verifying those summaries and/or views against the primary source material
132.5.    relies on the opinion of other experts in the knowledge that they did not have all relevant facts/documents before forming a view
132.6.    fails to acknowledge where factual disputes may be relevant
132.7.    fails in his duty to mention all matters that are relevant to the opinions he expresses and anything that might adversely affect his opinion
132.8.    fails to mention the range of reasonable opinion and the extent of that range
132.9.    suggests to the court that opinions of others (in this case neuroradiologists) have been taken into account when they have not
132.10. misquotes another expert and therefore acts in way which is likely to mislead the court
132.11. fails to grasp what research (within his own expertise) demonstrates
132.12. misrepresents what research says and/or shows
132.13. comes to the case with a preconceived opinion which he is then unreasonably reluctant to revise, even in the face of clear evidence
  1. Reverting to the allegations pursued by the Local Authority the court is able to find as follows:
133.1.    The court is asked to determine that the injuries were caused as a result of a minimum of 2 impacts – not established,
133.2.    that they would not have been caused as a result of a simple fall from 4 to 5 feet – the parents’ case is a complex fall from a slightly greater height with added spin. The mechanism described is not the one the court was asked to consider. The court accepts the mechanism described by the parents could have caused the injuries sustained.
133.3.    the injuries were caused as a result of a blunt or crushing injury to the Child’s head – everyone is agreed that this was a complex fall onto a flat, hard surface with downward and rotational force.
133.4.    the court is also asked to consider whether the sustained injuries were inflicted by either of the parents – not established; and
133.5.    that the parents had not provided an accurate account of how the injuries were sustained – accepted as inaccurate by the Local Authority before the hearing commenced. It is accepted the accounts given by the parents were consistent from the outset
  1. The parents spoke about complete exoneration. The Local Authority spoke about rare circumstances where there is not a basis on which the court can make a finding. The court is able to go so far as to say there is no evidence before the court on which the court could make any finding other than that the injuries were caused accidentally, as stated by the parents. In accordance with the binary approach, henceforth it must for all purposes be treated as having been caused by accident.
  1. Mother seeks further findings against GOSH, [Dr G] and Professors [O] and Sellar. The court would respectfully point out that it is not for the parties to define the nature or extent of the findings the court should make. GOSH was not a party to these proceedings. [Dr G] may have attended as a treating consultant to give evidence, on behalf of GOSH, but he was not GOSH and he was not authorised to legally represent GOSH. He also falls into a different category of witness to [Professor AM] and Professor Sellar, because he is not an expert authorised by the court.
  1. [Dr G] expressed his opinion in his letter of [Day 21], which he was entitled to do. He was not providing an expert opinion for the court and was therefore under no obligation to reference the consensus statement or accept it. He also explained, in the witness box, that he was relying on the history given to him and his clinical experience. When expressing his opinion it is a matter for him what weight he chooses to attach to what evidence. It should also be noted, as he was not an expert before the court he was not on proper notice that findings may be sought against him.
  1. Mother seeks findings that Professor Sellar failed to be honest and open with the court when preparing his report and did not act with the integrity to be expected of an expert witness in that he:
137.1.    Failed to read and consider the Child’s medical records and the analysis of the scans but relied on the report on a scan undertaken by the general radiologist at the Watford general hospital when, had he considered the records, he would have seen the reports from the various consultants at GOSH even if he did not have the consensus opinion.
137.2.    Failed to follow the letter of instruction asking him to comment on the hospital radiology opinion.
137.3.    Gave unsatisfactory evidence as to when he received the medical records and when (if at all) he ever considered them.
137.4.    If as he says he was unable to access the records sent to him, failed to ask the guardian for an accessible version of the records before reporting to the court.
137.5.    Misrepresented the report of [Dr N] by giving the impression that [Dr N] had described the accident as a “stamping” either expressly of by implication when [Dr N] did no such thing.
137.6.    Failed to provide the full Weber paper and misrepresented the research of Weber when he described Weber as supporting the notion that the skulls of the cadavers were dropped head first and suffered fractures which crossed the sutures.
137.7.    Failed to read and consider the literature provided by the neuroradiologists even before giving his evidence to the court citing that he did not have enough hours in the day and thus was unable to advise the court properly or at all.
137.8.    Even when faced with incontrovertible material undermining his opinion failed to take into account such material when giving his evidence but rather raised matters not raised in his report namely the suggestion that soft tissue damage would run the whole length of the fracture line and the fracture would cross the suture in the case of a single impact.
137.9.    In his evidence sought to obfuscate so as to conceal the obvious fact that he had been at least careless in the preparation of his report, the experts meeting and the giving of his evidence.
  1. The court has already discussed a considerable amount of Professor Sellar’s evidence. The court is satisfied the observations and findings already made are appropriate and in accordance with the guidance in Re W (A Child). The court does not accept, however, that it is appropriate to make findings of dishonesty against Professor Sellar without at least giving him a further opportunity to be heard on the point. The court has to consider whether it is appropriate to extend these proceedings further to allow him an opportunity to be heard on the issue and the simple answer is it is not. It is not a proportionate use of the court’s time and resources, while taking into account the need to allot resources to other cases.
  1. The Local Authority does not oppose publication of the judgment, and in fact states there is a public interest in doing so, in particular highlighting the lack of understanding of such injuries. Mother agrees, stating this is an important case and it is right that it is in the public interest that the issues relating to this type of fall and the medical/radiological opinion and what is expected of experts giving evidence to the court should be known in particular by legal and medical professional. Father supports Mother’s view. The Guardian agrees publication of the judgment is in the public interest as:
139.1.    It is necessary for the public to understand the lack of knowledge regarding injuries of the nature suffered by the Child and the limited research available on the subject.
139.2.    It is in the public interest to understand the limitations of expert evidence.
139.3.    It is in the public interests to understand how expert opinion can be misleading and the importance of experts being properly prepared and fully exploring alternative explanations when reaching their conclusions
  1. The court reminds itself a decision in the Family Court is not binding on other courts, although it may be persuasive. It is not for the Family Court to make new law on the expectation of evidence of a medical professional. At the same time, publication is in accordance with transparency and would appear to be in the public interest. Therefore an anonymised version, removing all reference to the names of the parents, children, family, hospitals and treating consultants (see below) will be required, along with dates being removed, to a schedule which will not be included in any published version and should be agreed by the parties.
  1. Mother seeks to argue [Dr G] and [Dr N] should be named in any published version of the decision. Father appears to seek to add [Dr W] from GOSH to the list. In relation to whether the professionals and / or hospital should be named, the Local Authority is neutral on this issue. The court is reminded it will need to be satisfied that any witnesses are sufficiently aware that adverse judicial findings and criticism may be made.
  1. The court is not satisfied it is appropriate to name any of those professionals in any published version of this decision. They are not experts in the case, so are not on proper notice of such. [Dr N] was not instructed on an ongoing basis, was provided with limited information, was not aware of the development of the evidence, may well have accepted his view could not stand if asked in light of the additional information and was not asked to attend to have his report challenged. [Dr W] was not called to give evidence. The court reminds itself that the court should not do anything to dissuade experts from providing the assistance that the court needs. [30] Publication of the details of the consultants and hospitals is also likely to increase the risk of jigsaw identification significantly. However, the court accepts the decision of the court may be of assistance to GOSH and the treating consultants when considering safeguarding in future and therefore is satisfied a full copy of the decision should be supplied to GOSH, along with the closing submissions of the parties.
  1. Mother argues the decision should be published with the names of [Professor AM] and Professor Sellar, who were both named court appointed experts. She says there is a significant public interest in them being named. A concern is that these are experts currently working as expert witnesses in family courts as well as giving evidence in many other matters. Father agrees.
    1. It was put to both witnesses on behalf of mother that their preparation of this case was careless at least, in the case of Professor Sellar also misleading, and as a result the parents have been put through an appalling ordeal. Without wishing to minimise such, the court reminds itself the evidence of both experts was obtained after proceedings had been issued. Neither expert was fundamental to the decision to proceed to court.
  1. Father reminds the court of how [Professor AM] responded to cross-examination, considered the further documentation provided and faced up to and accepted matters put in cross-examination. This stood in stark contrast with the evidence of Professor Sellar.
  1. The mother’s position is that regardless of what names (if any) are to appear in the published decision, a copy of the decision with no anonymisation should be provided to the General Medical Council (GMC) and that permission be given for transcripts of the various witness evidence be obtained either at the mother’s or the GMC’s request in due course. Permission is also sought for the papers in these proceedings to be disclosed in their entirety to the GMC as may be required.
  1. The Local Authority does not oppose a version of the judgment which is not anonymised being disclosed to any professional body if such permission is sought from any party. Father does not oppose disclosure to the GMC. Neither does the Guardian. The court is satisfied this is not an issue on which Professors [O] and Sellar are entitled to be heard and the matter can be determined now. The court is satisfied it is in the public interest to give permission to the Mother to disclose the full judgment to the GMC and, should it be required, to obtain transcripts of the evidence of both witnesses.
  1. It is the view of the court that before deciding whether the names of Professor Sellar and [Professor AM] should be published they should be given the opportunity to be heard on the issue. The court has included dicta from A v Ward to focus the mind in that regard, but they may wish to take legal advice. Therefore, a copy of the draft judgment should be provided to them and they be asked to provide, within 21 days, written submissions on the issue of publication of the judgment with their names to be included, rather than anonymised.
  1. Finally, the court wishes to thank the advocates for their assistance and the parents for their patience.