Not later. In the report.
If an expert opinion depends on incomplete data, assumptions or qualifications, those limitations belong in the written report.
- Not in cross-examination.
- Not in re-examination.
- Not only after the tribunal asks the right question.
In Mew v General Dental Council [2026] EWHC 1116 (Admin), the High Court considered expert evidence given during professional disciplinary proceedings.
One expert had deliberately avoided setting out limitations in the available data, believing that they could instead be explained when he gave oral evidence.
Charles Bagot KC, sitting as a Deputy High Court Judge, said that this revealed a “fundamental misunderstanding” of the obligations of a CPR-compliant expert.
The problem was not that the evidence required qualification. Many expert opinions do.
The problem was that the qualification had been withheld from the report.
A court or tribunal must be able to understand:
- what the expert can conclude;
- what the expert cannot conclude;
- where the evidence is uncertain; and
- how those limitations affect the strength of the opinion.
A carefully expressed qualification does not weaken expert evidence. It allows the decision-maker to assess it properly – and will often make the opinion more credible.
The expert report should contain the opinion the expert can genuinely support, not an unqualified version that appears more persuasive on first reading.
Read the judgment:
https://www.bailii.org/ew/cases/EWHC/Admin/2026/1116.html