The High Court Judgment That Renders an Expert’s Report “Unreliable”
A recent High Court judgment in, Rebecca Hepworth v Dr Amanda Coates [2025], serves as a stark reminder that expert credibility can be destroyed by fundamental preparation failures. The case shows how even well-intentioned professionals can fatally undermine their evidence and their client’s case.
A Summary of The Case
Rebecca Hepworth, a 27-year-old flight attendant, brought a clinical negligence claim against her GP, Dr Amanda Coates for allegedly failing to diagnose red flag symptoms of Cauda Equina Syndrome (CES). The claim, seeking over £5 million in damages, ultimately failed on liability. A key reason was His Honour Judge Charman’s finding that the claimant’s expert evidence was “unreliable.”
Why the Expert’s Evidence Was Found Unreliable
Judge Charman identified two critical failures
Incomplete preparation
- The neurorehabilitation expert prepared his report and signed a Joint Statement without seeing crucial documents, including the claimant’s own witness statement and other experts’ reports. This led to “serious discrepancies” between his account and the claimant’s testimony.
- Poor response under pressure
- During cross-examination, the expert made an error about medical notes but refused to admit the mistake. Instead, he tried to justify it by searching for non-existent evidence. Judge Charman noted this “cast serious doubt on the reliability of his oral evidence generally.”
The judge’s ruling makes it clear that although the expert’s failure was born from a “lack of care and attention to detail and not any partisan intent”, the effect on the case was the same.
Key Learnings for Experts and Solicitors
The judgment offers a powerful and direct set of learning points for all involved in the expert witness process. The Expert Witness Institute (EWI) has also highlighted this case as a key learning point for the industry.
For Expert Witnesses:
Own your preparation
While solicitors should provide all documents, experts must actively ensure they have the complete picture. Ask for missing materials rather than proceeding with gaps.
Get the history right
Don’t finalise reports when there are inconsistencies in the evidence. Flag these to your instructing party immediately.
Admit mistakes
If you’ve made an error, acknowledge it directly and explain how it affects your opinion. Attempting to justify obvious mistakes destroys credibility.
For Instructing Solicitors
Ensure All Documents Are Sent
Ensure experts receive all relevant materials, including witness statements and other expert reports. Consider implementing tracking systems.
Quality control matters
The case demonstrates why thorough preparation and review processes are essential for maintaining the integrity of expert evidence.
The Broader Message
Expert credibility isn’t guaranteed, it must be earned and protected through preparation and honest testimony. The Hepworth judgment shows that good intentions aren’t enough. Professional diligence, complete preparation, and honest acknowledgment of limitations are non-negotiable requirements for reliable expert evidence.
Protecting Your Case
The consequences of unreliable expert evidence extend beyond individual cases, they undermine confidence in the entire expert witness system. This is why our managed service model focuses on preventing these issues before they occur.
When you instruct Psychology and Psychiatry Direct, you’re not just accessing expert witnesses, you’re partnering with a team dedicated to maintaining the highest standards of professional integrity and case preparation.
