The admissibility of opinion evidence

Syed Rahman of Rahman Ravelli details a case that saw the court deny permission to use expert evidence

In accordance with CPR 35, in order for opinion evidence to be admissible in court, it must be relevant and prepared by someone who would be qualified to give expert evidence. A party cannot rely on expert evidence without the court’s permission.

There will be occasions, however, when parties attempt to smuggle opinion evidence into witness statements, whether consciously or not. When this has happened, judges are critical of such attempts. This was demonstrated in the recent case of Penhallurick v MD5 Ltd [2021] EWHC 293 (IPEC). HHJ Hacon identified a witness statement served by a party as being inadmissible, as it was considered as an attempt to adduce expert evidence without permission.

Case summary

In this case, the claimant (Mr Penhallurick) claimed ownership of copyright on various works. He alleged infringement of his copyrights by the defendant, which was his former employer (MD5).

One witness, Mr Clark, who was called by the defendant, gave a statement which the judge found to be inadmissible given that it contained “expert” evidence.

At an earlier case management conference, the defendant was granted permission to file further witness statements to provide an explanation to help the judge understand the disclosure of the claimant. HHJ Hacon noted, “I had no prospect of properly understanding Mr Penhallurick’s late disclosure without some informed assistance and not just from Mr Penhallurick”. However, the judge had granted no permission to either party to file expert evidence.

Mr Clark’s opinion as to the actions of the claimant, which was contained within his statement, was considered exactly that - an opinion.

What is expert evidence?

Essentially, expert evidence is opinion evidence - the opinion of the expert. The primary function of the expert witness is to assist the court in reaching its decision by providing independent expert/technical analysis and opinion on an issue or issues, based on the information provided by those instructing him/her. 

In appropriate cases, an application for striking out irrelevant or inadmissible evidence can be of considerable tactical value. It can be very embarrassing for lawyers to have to explain to their clients that the many thousands of pounds spent on the witness statement exercise has been mis-spent.

The above case highlights the importance of instructing well-regarded legal representatives who can identify the distinction between opinion and factual evidence and, therefore, avoid circumstances where witness statements are deemed inadmissible by the court.