Why Real-World Expert Witness Experience Matters: Lessons from Abbott & Ors v Ministry of Defence
When two experts disagree, the court has to decide who to believe. The High Court judgment in Abbott & Ors v Ministry of Defence [2026] EWHC 941 offers a clear and informative example of exactly how that decision gets made, and why the credentials on an expert’s CV are only part of the story.
The Case in Brief
Abbott & Ors v Ministry of Defence is the lead judgment in what has become known as the Hugh James Military Deafness Litigation, a group of claims brought by former members of the armed forces for noise induced hearing loss (NIHL) and tinnitus sustained during military service. The litigation involves thousands of claimants, with two lead cases, Mr Christopher Lambie and Mr Jack Craggs, selected to determine a series of generic issues that bind the wider cohort. Judgment was handed down by Mr Justice Garnham on 24 April 2026, following a trial that ran across nine weeks in late 2025.
While much of the judgment addresses highly technical questions of audiology, diagnosis, and quantification, one part of it speaks directly to anyone instructing expert witnesses, regardless of the field: the judge’s assessment of the two expert witnesses instructed in Mr Lambie’s case.
Mr Justice Garnham found that the claimant’s “progress through the ranks was remarkable; at almost every stage he was marked out as someone fit for promotion and then achieved that promotion and managed the new role with conspicuous success.” The judge considered Mr Lambie’s choice of an intelligence career to have been a sound one, allowing him to pursue an interesting path both during and after military service while properly managing his hearing disability.
The court awarded £64,800 for loss of future earnings, considerably below the £370,000 claimed. Notably, this figure was not derived from preferring one expert’s figures over the other’s. Instead, the reasoning rested on the unpredictability of any organisation’s future and the possibility, even if unlikely, that Mr Lambie could at some unpredictable point over the next fourteen years find himself back in the job market.
The Two Expert Witnesses
In considering Mr Lambie’s claim for loss of future earnings, the court heard from two employment consultants: Mr Hailstone, instructed by the Ministry of Defence, and Mr McKerns, instructed by the claimant. Where their evidence diverged, Mr Justice Garnham was clear about which expert he preferred, and why.
The judge described Mr Hailstone as a former Naval officer with a strong understanding of Mr Lambie’s former career, substantial consulting experience, and evidence the judge regarded as balanced and authoritative. He found Mr Hailstone to be a witness who demonstrated genuine expertise and, importantly, independence of thought.
Mr McKerns, by contrast, was found to have no experience of the military or defence sector, no experience of cyber security, and no experience of management consulting beyond his own narrower professional background and a single conversation held the day before he gave evidence. The judge noted that Mr McKerns’ evidence relied on Mr Lambie’s own account of his career and prospects, with little apparent effort to test or challenge what he was told. The judgment records that his evidence showed limited analytical rigour.
Why This Matters for Anyone Instructing an Expert Witness
This is not a case about one expert being dishonest or unqualified in any formal sense, both held relevant professional credentials. The distinction the court drew was about something more practical: did the expert have the lived, real-world knowledge of the relevant field to properly test and evaluate the evidence in front of them, or did they simply accept what they were told and repeat it back?
That distinction matters when selecting an expert witness. A few takeaways:
- Sector-specific experience carries real weight
- Independence of analysis is not optional
- A considered, well-prepared analysis matters
- Credentials alone do not guarantee persuasive evidence
For solicitors and legal professionals instructing expert witnesses, Abbott v MoD is a useful and timely reminder. The strength of expert evidence can be about whether the expert understands the world they are commenting on, and whether they are prepared to interrogate the evidence rather than simply reflect it back.
At Psychology Direct, finding the right expert for the right case is something we think about carefully, and cases like this are a helpful reminder of why that matters.
If you are instructing an expert witness and want to discuss how to find the right fit for your case, get in touch with our team.
