Some aspects of litigation are highly reliant upon experts. Medical causation is on of those areas. The issues between experts should be clarified in the joint statement. In Smith -v- Tesco PLC & Royal Free London NHS Foundation Trust  EWHC 3252 (QB) David Pittaway QC considered a case in which an expert raised a new theory after the joint report. The late advancement of a new theory is rarely helpful to a party seeking to prove matters at trial.
“The late advancement of this opinion is, in my view, very unsatisfactory and if a live issue should have been considered at a much earlier stage and permission sought to rely on urology evidence. It defeats the purpose of exchange of expert evidence and joint discussions between experts if experts raise new theories shortly before trial.”
The claimant was injured at work. One of the issues before the court was causation: the extent to which the accident caused an injury to the claimant’s back.
THE JOINT REPORT AND THE SUBSEQUENT NEW THEORY ADVANCED BY THE DEFENDANT’S EXPERT
The judge commented on the differences between the doctors and the production of the joint medical report. There was, however, a subsequent development with a new theory being advanced by the doctor instructed on behalf of the defendant.
- The joint statement agreed that Mr Smith had symptoms of low back pain with radicular features affecting the left leg prior to the accident in 22ndMarch 2011 consistent with posterolateral disc protrusion. They are agreed that Mr Smith’s “onset of symptoms of severe low back pain and subsequent symptoms of cauda equina with an acute onset with rapid progression following the index event, are in keeping with [Mr Smith] having suffered a sequestered fragment at the time of the index event.”. They are agreed that the entries in the hospital records are contradictory and required clarification. No further witness evidence has been provided. Otherwise they maintained their respective positions on causation set out in their reports. There is no mention of urinary retention in the joint statement.
- Shortly before trial Mr Porter produced a further report in which he continued to maintain that the Mr Smith was already in the cauda equine syndrome before the accident on 22nd March 2011. His opinion, however, was based upon a new hypothesis, namely that the two episodes of incontinence after 0600 were in keeping with overflow incontinence and as a result Mr Smith had already entered cauda equine syndrome in retention some hours before the accident. He postulates that overflow incontinence will occur where patients have a bladder volume of 800-1000 mls some hours after the onset of bladder paralysis. He considers that it would take a number of hours to establish that level of urine. He considers that there would be distress at 400 mls of urine in the bladder and retention at 500 mls. He speculates that Mr Smith had a full bladder at the time of the index event. He defers to the opinion of an urologist but adds that a neurosurgeon is expected to recognise and manage immediate bladder problems associated with the condition. He considers that Mr Smith’s acute back pain immediately after the accident arose as a consequence of a further additional sequestered fragment of disc, which had no material effect on his outcome.
- Both experts are agreed that cauda equine is a very rare condition but that disc degeneration is very common as is disc prolapse. Mr Porter accepted that most people who suffer extrusion or sequestration do to not go on to develop cauda equine syndrome. He accepts that Mr Smith did not display symptoms until after the index event. Where he differs from Mr Sakka is his view that he developed urinary retention as a result of a sequestration of the disc before the accident, which was caused by another event or spontaneously to a vulnerable disc. He considers that the disc fragment move inferiorly compressed the central nerves at some point during the evening of 21st March 2011. He accepts that urinary retention is central to his opinion. He also accepts that at the time he prepared his first report urinary retention did not appear to him as central to the case. He also accepts that he has not met a case of this type in his clinical practice.
- After careful consideration I have preferred the evidence given by Mr Sakka to that of Mr Porter. The opinion in Mr Porter’s first report, in my view, is largely based on two factors that have turned out not to be correct, namely, the note made by the neurosurgical registrar at the Royal Free Hospital that Mr Smith was incontinent at midnight before the accident and his own history that Mr Smith was experiencing numbness in his buttocks at 0230. On any view the neurosurgical registrar’s note cannot be correct and must have been an incorrect transcription or relaying of the history that Mr Smith gave him. I have already concluded that Mr Smith probably incorrectly relayed his history to Mr Porter on 21st March 2015.
- There is no suggestion in Mr Porter’s first report that he considered that the Mr Smith was in urinary retention at the time of the accident. His opinion, as I think he recognises, is at the boundaries of his expertise when he gave evidence about the amount of urine that was required to be retained before it overcame the muscular controls of the body. The late advancement of this opinion is, in my view, very unsatisfactory and if a live issue should have been considered at a much earlier stage and permission sought to rely on urology evidence. It defeats the purpose of exchange of expert evidence and joint discussions between experts if experts raise new theories shortly before trial. It seems to me that Mr Sakka’s explanation is correct that by the time that Mr Smith’s urinary incontinence occurred the cauda equine syndrome was complete. There is an inescapable logic that when he went upstairs he was uncontrollably incontinent and once he had found the lavatory he was unable to pass urine because, at that time, there was no more urine to pass.
- In these circumstances I have reached the conclusion that Mr Smith, who was suffering from a vulnerable back, sustained a sequestered disc when the one or more wheels of the tug struck the sunken fire hydrant on 22nd March 2011. I reject the theory postulated by Mr Porter that Mr Smith was already in urinary retention by the time of the accident. There is nothing to suggest that he was suffering from red flag symptoms of cauda equine syndrome before the accident, or indeed, that he was unable to carry out his duties before that time. It follows that I am satisfied, on the balance of probabilities, that the accident caused Mr Smith’s cauda equine syndrome.”
Experts changing their minds
For another example of where an expert changed their minds after the joint report see:
- The dangers of relying on expert evidence
- The interchange between lawyers and experts: a difficult issue
- Experts and facts: it is all in the rules.
- The role of the expert witness in litigation: Supreme Court Guidance
- Expert reports: too long and not much use.
- More on experts: non-compliance with the rules taints the evidence badly
- The credibility of witnesses: joint meetings and overreaching experts: a case to point.
- Over eager experts just do not help: they hinder and harm the case of those who call them.
- Beware the expert evidence who “lectures” the court (and tells the judge who to believe).
- Expert evidence about the veracity of witnesses: well, its probably a waste of time.
- An expert must disclose details of professional relationship with a party otherwise the consequences can be dire.
- Irrelevant evidence, inferences and “forgery”: evidential issues in a High Court case.
- Principles of mitigation of loss & the credibility of expert witnesses.
- I didn’t mean it when I signed the joint report: what happens when experts change their minds?
- Expert evidence: the expert’s role: seeing the wood for the trees.
- Cross-examining expert witnesses: hints, tips and links.
- Experts going on a frolic: a family law case where the expert witness was “thoroughly unhelpful”.
The proving things series
- Proving things 1: Civil Evidence Act notices will not cut it
- Proving things 2: evidence to support a claim for damages must be pitch perfect.
- Proving things 3: the complete absence of evidence means the court will not speculate
- Proving things 4: Witnesses who just aren’t there.
- Proving things 5: witness statements and failing on causation.
- Proving things 6: “That’s what I always do” & proving causation.
- Proving things 7: If you don’t prove a loss you don’t get an order.
- Proving things 8: a defendant must prove that a failure to wear a seatbelt made a difference.
- Proving things 9: the role of experts
- Proving things 10: “He said, she said”: the difficulties of recollection.
- Proving things 11: Lies, damn lies and…
- Proving things 12: That oral contract is not worth the paper its written on.
- Proving things 13: Loss, there was no loss.
- Proving things 14: proving mitigation of loss
- Proving things 15: damages and evidence: going back to College
- Proving things 16: if you don’t prove it you don’t get it.
- Proving things 17: Heads of damage that were “entirely bogus”
- Proving things 18: Damages; Car hire; Proof & Summary Judgment
- Proving things 19: prove service or you could be caught out.
- Proving things 20: allegations of improper conduct have to be prove
- Proving things 21: when the whole process of investigation is flawed
- Proving things 22: damages, mitigation part 36 (and bundles).
- Proving things 23: serving important evidence late
- Proving things 24: Damages & the “But for test”: when it gets really complexProving things 24: Damages & the “But for test”: when it gets really complex
- Proving things 25: Attempts to smuggle in witness statements do not help (and carry no weight).
- Proving things 26: distinguishing between what you can remember and what you now think you did.
- Proving things 27: Burdens of proof, hearsay evidence and… attempted murder.
- Proving things 28: make unwarranted personal attacks and use a “mud-slinging” expert: that always ends well.
- Proving things 29: Make sure the witness evidence deals with the relevant issues
- Proving things 30: Office Gossip Proves Nothing: The importance of the source of information and belief.
- Proving things 31: witnesses tend to remember what they want to remember.
- Proving things 32: Damages claim struck out as unsustainable: application to amend refused.
- Proving things 33: causation and the burden of proof in claims against solicitors.
- Proving things 34: There is no primer for scuttlers: when your ship doesn’t come in.
- Proving things 35: Reconstruction, documents & memory.
- Proving things 36: credibility and contemporaneous documents.
- Proving things 37: An approach to damages that was “fundamentally deficient throughout”.
- Proving things 38: Proving inability to pay on a security for costs application.
- Proving things 39: You can spend £10 million in costs and still not prove your case.
- Proving things 40: No evidence – no loss.
- Proving things 41: Proving damages – you are not going to get a second bite of the cherry.
- Proving things 42: silence does not prove inducement.
- Proving things 43: How the Court decides: a Primer.
- Proving things 44: Findings of Fact, Walter Mitty and Witness Training.
- Proving things 45: If you can’t prove loss the defendant is going to get summary judgment.