“The expert had only skimmed the papers.”

Few expert witnesses would want to read those words in a judgment.

In Re X and Y (Care Proceedings: Publication of Judgment: Criticism of Expert Witness) [2026] EWFC 132, Mrs Justice Knowles decided that the consultant neurosurgeon should be identified following serious criticism of his conduct as an expert witness. That decision followed the court’s detailed findings in Re X and Y (Care Proceedings: Fact Finding: Death of a Child: Expert Evidence) [2025] EWFC 132.

The criticism went far beyond inadequate preparation.

The court found that the expert had not properly engaged with the available evidence, had strayed beyond the limits of his expertise, had failed to engage adequately with the opinions of other experts, and had advanced conclusions based on speculation rather than a sound evidential foundation.

The case is a reminder that expert evidence is judged not only by the conclusions reached, but by the process used to reach them.

An expert opinion carries weight because it is the product of careful preparation, objective analysis and transparent reasoning.

Before accepting an instruction—or before entering the witness box—it is worth asking:

✔️ Have I fully engaged with all the relevant material?

✔️ Am I remaining firmly within my own expertise?

✔️ Have I fairly considered competing expert opinions?

✔️ Can I clearly explain the evidential basis for every conclusion I have reached?

The role of an expert witness is not to persuade. It is to assist the court with independent, balanced and properly reasoned evidence.

📖 Judgments:

Re X and Y (Care Proceedings: Publication of Judgment: Criticism of Expert Witness) [2026] EWFC 132
https://www.bailii.org/ew/cases/EWFC/HCJ/2026/132.html

Re X and Y (Care Proceedings: Fact Finding: Death of a Child: Expert Evidence) [2025] EWFC 132
https://www.bailii.org/ew/cases/EWFC/HCJ/2025/132.html

 

Some specialist areas of expertise are so niche that it’s almost impossible to find experts who are free of previous involvement with one or more parties to a dispute. In a recent case requiring expert evidence in mine surveying (Cleveland Potash Ltd v Drummond & Ors) not only had both experts been involved with the parties they had worked in the same office as each other for 20 years!

In this case both experts were clear and transparent about their previous involvement and as the  judge explained, “Whilst neither party raised any concerns about the experts’ prior and ongoing involvement in the issues related to this dispute I will have to consider that involvement as part of my overall assessment of the experts. I remind myself that the experts have an overriding duty to the court which should override their duty to their clients.”

It seems that one expert was much more successful in retaining her objectivity than the other, reading the judge’s explanation gives some important pointers for all experts as to how to do this, specifically;

“Mrs Iwanicki was a very impressive witness. She was deeply knowledgeable about her subject. She gave clear, careful, well considered and measured answers to the questions she was asked. She had a good understanding of her overriding duty to assist the court rather than to advocate for a particular position. Her answers were honest and straightforward even where those answers might have been seen as providing some assistance to Rs. That is what the court expects of an expert witness who understands that their role is not to advocate for a particular party or outcome but to assist the court.

 

Mr Troman was also clearly very knowledgeable about his subject, however, unlike Mrs Iwanicki on some occasions he did not appear able to disassociate his longstanding role of assisting the Rs (and other leaseholders) to negotiate what he considered to be a satisfactory outcome with CPL from his duty to assist the court. This more partisan approach had infected some of his evidence and the contents of his report. It was clear from his evidence that he felt that other mineral rights owners who had now agreed terms with CPL should have held out and/or would have done better if they had followed his advice/recommendations. He was reluctant to accept the possibility that the conclusions in his report might need to be adjusted or modified even when it became apparent that there were factors or information that he had not known about and could not therefore have taken into account when reaching his conclusions. His resistance to accepting any possibility that his conclusions on valuation might need to be adjusted was unhelpful and undermined his position. Further he had a tendency to speculate both in his report and in his evidence and on at least one occasion asserted a factual position which turned out not to be true. Overall, this approach undermined his credibility and the weight that I give his expert opinion.

 

As always the key for any expert is to ask yourself ‘what would I say if I was acting for the other side?’. If the answer is in any way different then you need to think again. For guidance on what to do if you have been involved with a party to a dispute and other issues relating to conflicts or perceived conflicts see our guidance on the subject.

Our image is from the New Scientist

 

The High Court ruling against Danish tax authority SKAT in a £1.4 billion dividend tax fraud case has been widely reported, not least because the judge concluded that SKAT’s controls on the transactions involved were so flimsy as to represent the equivalent of a ‘help yourself’ sign outside a bank.

 

Less attention has been given to the judge’s criticisms of the experts who appeared on behalf of the many parties involved. As he put it “ All three experts, in differing ways, did not provide properly balanced written reports”.

 

Perhaps the clearest example was SKAT’s expert “whose written work was argument rather than expert evidence” showing the dangers of working closely with a client and legal team on complex, long-running litigation. The judge concluded that “he finds it difficult not to think and express himself as an advocate for SKAT’s position. He has, I think, lost detachment from the partisan interests of SKAT” and was unable perhaps to hear any ‘evil’ in his client’s case.

 

Somewhat less concerning was an expert whose testimony was careful but tended to obscure his views and maximise differences with other experts that were not a pronounced as appeared at first glance.  As the judge observed, “That exposed him to a cross-examination that should have been largely unnecessary to confirm the extent to which, in substance, he agrees with a range of matters on which SKAT relied. “ Fortunately he appears to have dealt with that cross-examination impressively, fairly (with balance), and with an obvious depth of thought and expertise. A better approach might have been to write a report that allowed the parties to see more clearly.

 

And finally, the third expert’s generally much better approach (once his reports had been edited to remove contentious factual matters that should not have been there!) and thoughtful and fair answers to questions were undermined by his taking a view in the witness box that he had not expressed in writing.  The judge concluded that his interpretation of a key terminology expressed in oral evidence “had not been his view at any material time. It was inconsistent with the views he had expressed in writing, including in his primary expert report in these proceedings, to which he had to proffer alterations when called to give his oral evidence to advance the different view. “  While the case did not turn on this point the judge made it clear that speaking out in this way, because his written views in fact assisted the other side, was not acceptable and did the expert no credit.

 

The message to experts should not be a surprise, no client’s case is perfect and there are times when your views will not support their case. When that happens it is critical that you make sure your client’s hear you, that the court can see hat your views really area and that when you speak you keep your duty of independence firmly in mind.

Anyone considering acting as an expert needs to understand that environment,  the rules that apply to expert evidence and how to avoid the pitfalls that can lead to a difficult time in court and potentially public criticism from a Judge.

The Academy’s training programme is designed to help already  skilled professionals through the basic foundations to a mock cross-examination to ensure that they are fully prepared. Our training courses are primarily delivered online but we run some face to face courses  in London and Hong Kong. We can also run in-house training for larger consultancies, please contact us for details.

The Criminal Procedure Rules Committee have issued a new consolidated set of the Criminal Procedure Rules which came into force on 6^th October 2025.

The Criminal Procedure Rules 2025 replaces the Criminal Procedure Rules 2020 and incorporates the 9 sets of amendments made since the 2020 rules were published. The Committee has also published a guide to the new Rules. criminal-procedure-rules-2025.pdf

In addition, the Criminal Procedure Rules Committee have just published the. Fourth Amendment to the Criminal Practice Directions 2023 – November 2025 – Courts and Tribunals Judiciary. The changes, some of which will impact on experts in Chapter 7, come into force on 18^th November 2025.

The amendments:

1. require the disclosure in an expert report of any authoritative advice or warning relevant to the content of the report;
2. require the disclosure in an expert report of any past adverse finding or disciplinary proceeding, even if since resolved; and
3. ensure the compatibility of the declarations of compliance required by (i) the Criminal Practice Directions, and (ii) the Forensic Science Regulator’s statutory code of practice.

Updated Expert Declaration
In addition to the changes outlined above there are also changes that need to be made to the Expert’s Declaration, full details are on the Academy website.

 

Don’t forget to update any templates you have that are effected by the changes and to satisfy yourself that any report issued after 18^th November 2025 complies with the new requirements.

Most discussion (and criticism) of experts revolves around issues where experts disagree, often in ways that are pivotal to a case.  But there are many cases that go unnoticed where experts agree on most, if not all, of the important issues, which for the most part is what you would expect from professional experts given the same set of facts and questions.

 

The value of agreed evidence was highlighted in a recent professional negligence case involving a very unpleasant spinal condition called Cauda Equina.  Working through all the issues  required evidence from experts in GP practice , neurosurgery, urology, psychiatry, neurorehabilitation, physiotherapy and occupational therapy. It’s evident from the judgement that most of the experts involved were experienced  professionals and the judge was greatly assisted by the extent to which evidence was agreed as shown by these quotes;

 

“I found both to be clear and helpful in their evidence and each engaged with the questions they were asked and sought to assist the Court with their answers. Each also made appropriate concessions. Most importantly, as they stated in the Joint Statement dated 31 July 2024, they agree all of the most important points.”

“I accept all of this agreed expert evidence, as does each of the parties. “

“Neither expert was cross examined for long as they are essentially agreed on all significant points. Both gave their evidence in a clear way and made appropriate concessions. I accept their evidence. “

“I accept all of the agreed expert evidence.”

 

“Both gave oral evidence at trial, although at no great length given the extent of the agreement between them as to the most important matters of urology in the case. I found both to be impressive witnesses, giving clear and direct answers to questions with helpful explanations where necessary. Each also made appropriate concessions. “

 

In contrast in a complex case involving bribery and corruption relating to oil exploration (Aaabar v Gemcore) an expert in Dutch law appears to have viewed the idea of agreeing with another expert as problematic. The issue concerned involved whether disclosure of certain materials would result in a criminal prosecution in the Netherlands. In his first report the expert said that prosecution “may” result but following a meeting with the other expert, who disagreed, firmed up his position to complete certainty but was unable to provide any explanation of why his position had changed.

 

As the judge commented while “it is understandable (as occurs with lawyers) to firm up one’s views after further analysis and consideration, experts are instructed to give their independent expert opinion, and are under a professional obligation to explain and justify any change of opinion. In this context it is somewhat strange that views expressed without considering another’s expert report should then be expressed in very much stronger terms after reading the report of another expert who expresses a contrary view with which the first expert disagrees.” His view was that the unexplained shift in ground called into question the reliability of the expert’s evidence.

The message for experts is to remember that your opposite number is not an enemy and that you should both, in most cases, hold the same opinions if presented with the same facts and questions. There may be good reasons for disagreement but disagreeing for the sake of it or to support your client’s case does not help the court nor in the long run you or your client.

 

For advice and guidance on meetings of experts and agreed statements of expert evidence check out the guidance in the Academy’s Knowledge Hub.

Most judicial criticism  of experts arises from either ignorance of the basic rules of expert evidence or because experts who understand and have tried to apply the rules have slipped off the straight and narrow  path, usually from a desire to help their clients.

So while judges comments are often direct and colourful they generally accept the understandable human urge to help and temper their criticism accordingly. However, from time to time experts  don’t just slip off the path they deliberately choose to jump off the cliff in pursuit of their client’s interests.

In Marples & Ors v Secretary of State for Education compensation was claimed from the Skills Funding Agency, the amount of which depended on expert evidence from a  forensic accountant.  Concerns were initially raised about involvement of one of the claimant’s, himself an accountant, in the production of a joint statement. Letters, witness statements and some document disclosure followed and it appears that over the course of what must have been a somewhat eventful hearing, to put it mildly, it became clear that the client had been heavily involved in the production of the joint statement.

We recommend that all experts read the judgement which culminated with the following conclusion from the judge;

1. This is a deliberate, cynical, planned breach of the rules relating to the preparation of expert evidence. It is a very serious breach.
2. The product of the expert in the shape of his report and the joint report are not independent. They do not represent his objective and unbiased opinion. They represent advocacy on behalf of the claimants, using words put in the expert’s mouth by the claimant. They represent what the claimant wants the expert to say and are not the expert’s opinion at all. This includes contributions on matters on which the expert avowedly knows nothing (such as Star Capital).
3. I have no confidence in this expert’s ability to act in accordance with his obligations as an expert witness.

I accordingly refuse the claimants permission to rely upon the evidence and reports of the expert.

Not surprisingly given this, and other issues with the factual evidence, the claim was dismissed.

We suspect that no amount of rules or  training can prevent the very few experts and clients who are determined to break the rules but for everyone else we would remind you that anyone considering acting as an expert needs to understand the role. That means knowing  the rules that apply to expert evidence and how to avoid the pitfalls that can lead to a difficult time in court and potentially public criticism from a Judge.

The Academy’s training programme is designed to help already  skilled professionals through the basic foundations to a mock cross-examination to ensure that they are fully prepared. Our training courses are primarily delivered online but we run some face to face courses  in London and Hong Kong. We can also run in-house training for larger consultancies, please contact us for details.

Experts rightly pride themselves on their knowledge and understanding of their specialist area but its fair to say that judge’s are sometimes less than impressed when expert evidence takes on a life of its own.

They particularly dislike expert evidence on subjects that really don’t require any expertise.  Glenfiddich Wind v Doranell Windfarm  was a dispute about wind power generation where two experts were asked to interpret and describe the UK’s Balancing and Settlement Code (BSC) which governs how energy generators are paid.  The problem the judge saw was that “their descriptions were not matters upon which they possessed any special knowledge or experience, and had no greater value than had they been expressed by someone plucked  at random from the street to whom the BSC processes had been described.” They had in effect, although knowledgeable and balanced in their approach, become conscripts in an expert arms race which had  grossly and unnecessarily complicated the presentation and consideration of the merits of the case

Even when expertise is genuinely required it can sometimes expand beyond sensible boundaries. In Energygen & Hyundai v HD Korea Shipbuilding   there was a need to know the correct translation of the phrase “sah-up-booh-moon” but as the judge explained, “I mean no disrespect to either expert when I observe that I doubt that quite so much academic firepower was necessary to resolve this very narrow issue. “

But in a different twist on the theme,  factual witnesses can sometimes over-emphasise the need for expertise.  DRPS Property  v Residential Marine was a dispute over a small parcel of land on the Medway that may or may not have existed at a particular point in time.

One of the factual witnesses explained, which the judge accepted, that she was not an expert on maps or plans. However, as he put it  the refrain that she was ‘not an expert’ “was trotted out any time that there was anything difficult or contrary to her case in any of the maps and plans, no matter how obvious the point was on the face of the document and how little expertise was needed to grasp the point”

So as so often, the rule is that witnesses, whether expert or not, should stick to what they know but avoid hiding either in denials of the obvious or in thickets of irrelevant material, however well informed.

Being instructed as an expert witness can be an interesting and fulfilling aspect of professional life, but it’s not without its challenges. One of the most common (and under-discussed) issues experts face is how to manage their instructing solicitors.

It’s easy to assume that once you’re engaged, expectations are fixed and your role is simply to deliver. But in reality, managing your instructing solicitor is a key part of ensuring that what you deliver is useful, compliant, and capable of standing up in court.

Academy Council Member Helen Gregory of Opus Forensic Accounting has helpfully provided her five top tips for how expert witnesses can work most effectively with their instructing solicitors.

1. Be realistic about deadlines — and say no if needed

There’s a temptation to take on every instruction that comes your way, particularly if you’re self-employed and don’t know where the next one is coming from. But accepting unrealistic deadlines can cause problems for all involved. Rushed reports are more likely to contain errors, lack clarity, or fail to meet procedural requirements. And in the worst-case scenario, they can be thrown out by the court entirely.

It’s better to decline a job than to submit something half-baked. Be clear at the outset about what’s feasible and remember to factor in time not just for writing the report, but for reviewing documents, requesting further information, meetings with the solicitor and client, responding to queries, and navigating any surprises.

2. Build in contingency: Something will crop up

In theory, you receive a neat, complete bundle of documents and a clear brief. In practice, things are rarely that tidy. Documents arrive late or in multiple batches, some are missing or out of order, and the questions you need to address will take time to answer.

You need to allow for contingency: time to request clarifications, review additional information, and think critically about what you’re being asked to do. The more flexibility you build in, the more likely you are to produce a report that is robust, complete, and helpful to the court.

3. Understand the limits of your visibility

One key challenge is that, as an expert, you often operate in isolation from the wider case. You may see only a snapshot of the full picture. It’s important to remain focused on your instructed area and resist the temptation to speculate beyond it.

At the same time, remember that lack of context doesn’t remove your duty of care. If documents appear incomplete, if your opinion feels influenced, or if something doesn’t sit right, you must raise it. You are reporting to the court, not acting as an advocate for either party.

4. Deliver bad news where it’s warranted

It’s not always easy to say your client doesn’t have a case. But as an expert witness, you have a duty to give your honest, professional opinion, even if that opinion isn’t what the instructing solicitor wants to hear.

Be aware that some may (consciously or otherwise) attempt to steer your opinion. Stay alert to missing evidence, biased questions, or subtle attempts to frame a narrative. Your integrity and credibility depend on your ability to remain independent and evidence-based.

5. Know the rules and review your report thoroughly

Expert reports must comply with the relevant Civil, Criminal or Family Procedure Rules. That includes formatting, content, and declarations. A technical report that omits the correct statement of truth or includes the wrong version risks being ruled inadmissible.

It’s also essential to re-read what you’ve written. That may sound obvious, but when deadlines loom and multiple drafts are flying around, it’s easy to miss a critical detail. The best option is to ask someone else unconnected to the case to read and cast it, but that may not always be possible so do make time to review your own work with a clear head.  You may be cross-examined on your report, so make sure you’re comfortable defending it.

Final thoughts

Whatever your discipline, acting as an expert means more than just knowing your subject. It requires planning, time management, self-awareness, and the confidence to push back when needed.

Clear communication with instructing solicitors, realistic boundaries, and careful preparation are vital. If in doubt, The Academy of Experts offers training, guidance and support to help navigate the more complex aspects of expert witness work.

Helen is a Partner at Opus Forensic Accounting, part of the Opus Business Advisory Group, and brings over 25 years’ experience in civil and criminal investigations, commercial disputes, and matrimonial matters. A trusted expert witness and active figure in the sector, including roles with The Academy of Experts and the South West Fraud Forum, she recently joined Opus, a national advisory firm with 14 offices, 35 Partners, and specialist divisions spanning restructuring, strategic advisory, forensic accounting, and equity.

Insights into expert practice in different jurisdictions can be very helpful, not least because they often show that there are good and bad experts everywhere.  DHV v Motor Insurers’ Bureau was an unusual case about the compensation due to a pedestrian injured by an insured driver in Spain. Various quirks of the law and the claim meant that it was heard in the UK but the judge needed to apply the Spanish Baremo  system (ready-reckoner in English) to assess the size of the claim.

This meant that the judge had to consider the evidence of 8 Spanish experts specifically accident reconstruction, Spanish law, actuarial and medico-legal experts. The results can only be described as mixed bag.

At the top end of the scale the judge praised the Defendant’s actuarial expert as “knowledgeable and also very fair-minded” reaching some conclusions that favoured the Claimant. The Defendant’s accident reconstruction expert was also careful and measured in his evidence, “always at pains to alert the court to the limits of his evidence and expertise and when challenged over a gap in the evidence accepted that he should have covered the specific issue.   Similarly their expert in Spanish law was “aware of his limitations and balanced”.

The Claimant’s actuarial expert was somewhat less useful to the court, having applied a “mix and match” methodology rather than strictly following Baremo and their accident reconstruction expert, while being given credit by the judge for the difficulty of giving evidence through an interpreter, was unimpressive in parts and of little assistance to the court.

The quality of evidence  sadly had yet further to fall. The Claimant’s Spanish law  expert was  “in certain vital respects an unsatisfactory witness” . This expert had copied from a colleague’s report, without citing it, initially denied copying and then excused it as resulting from the use of a ‘central database’ of material. Sadly that excuse was fatally undermined by the presence of details specific to the case that appeared word for word in both reports.

Heading down the scale the Defendant’s medico-legal expert, while “an engaging and affable character “ and eager to try to assist the court, was “at points unbalanced in his conclusions, not motivated by a hostile attitude towards the claimant, but rather an insistent adherence to his opinion being right. There were occasions when he only accepted the conclusions of other experts with reluctance. “

And bringing up the rear his opposite number had not only failed to read both sets of medical reports, something the judge charitably attributed to a misconception, but replicated a significant passage from an article in his report without attributing it.  Rather than simply admitting the error  he compounded it by offering obviously incorrect explanations in oral evidence. While nothing critical turned on the article these issues “caused the court to think carefully about his openness”.

There are many lessons to be learned from this judge’s careful review of the expert evidence, not least that judges are much more interested in facts and careful analysis than they are by  confident presentation and advocacy.  As Dias J put it “This case was not short of advocates; it needed impartial expert advice.”

Established members will be familiar with the Academy’s training courses which include mock cross-examination to ensure that new experts are fully prepared, and would not make the mistakes cited here. If it’s been some time since you attended training it may be worth considering a refresher. For example, many experts rarely give evidence in court so a repeat of ‘Into Court’ might be handy if you have a court appearance looming.

Most of our training courses are now delivered online so your location doesn’t matter and members receive a 25% discount.  We can also run in-house training for larger consultancies, please contact us for details.

A recent case about a snowmobile accident (Cannestra v McLaren Automotive Events) has been much commented on because the Claimant seems to have constructed a version of events somewhat at odds with his comments at the time that ”it was all his own fault” . But as the judge sat through the expert evidence from both sides he could have been forgiven for thinking he was trapped in a story with an unremittingly downward plot, like Hamlet or Kafka’s Metamorphosis.

At the top end of the scale was an expert whose report was “thoughtful and well researched. He gave evidence openly and flexibly, as an expert should. “  but the judge commented with some puzzlement at the omission, presumably for tactical reasons, of an opinion on a technical key issue in the case.

Stepping down a level an expert who was clearly doing his best to assist the Court and was “precise, logical and well prepared” was undermined by a tendency to focus on his party’s case and ignore the other side’s. An issue that in other circumstances might have drawn more substantive criticism.

Aa third expert managed to take things down another notch.  The evidence of a helpful and straight forward expert was  “deeply faulted by inaccurate and unlikely assumptions” not least that his assumption of maximum acceleration would have led to a completely different outcome than the accident that in fact took place.

But the nadir of the expert evidence was reached by an expert who appears to have taken an extraordinarily combative approach. The judge concluded he was “a partial witness who acted as an advocate for the Defendant’s case. He not only ignored the Claimant’s evidence and adopted the guides’ evidence, he positively sought to persuade the Court to find facts in the Defendant’s favour. His report was littered with errors and illogicality. His research on modes of operation of SMs was flimsy and unimpressive. He strayed into accident reconstruction. He made things up in the witness box and he estimated facts when the actual facts were staring him in the face.   I am unable to rely on the vast majority of his evidence. “.

Unfortunately experts can’t generally rely on their opposite numbers drawing judicial fire quite so effectively. So it’s critical to remember that where there are two factual versions of events an expert should consider both versions and any assumptions must be realistic and checked for illogical consequences.

For guidance on best practice such the Model Form of Expert’s Report and Guidance Notes on Meetings of Experts, Contingency Fees & Remote Evidence see the Academy’s Knowledge Hub.