Potential probative value outweighs criticisms of production of surveillance evidence in Perrin v Walsh [2025] EWHC 2536 (KB)

In Perrin v Walsh, criticisms about the production of surveillance evidence were outweighed by its probative value when determining admissibility. Daniel Millar, pupil barrister at 12KBW, highlights the practice points arising from this much-discussed case.

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Background

The admissibility of covert surveillance evidence has returned to the High Court in Perrin v Walsh [2025] EWHC 2536 (KB). The Claimant was injured in a road traffic accident, in respect of which liability was admitted. The Defendant contended that the Claimant exaggerated her injuries. Her representatives instructed a surveillance company to obtain video footage and applied for permission to rely on it.

The Claimant resisted the application. She submitted that the surveillance company had dishonestly obtained and processed the footage such that it should not be put before the trial judge.

Judgment

HHJ Grimshaw (sitting as a Deputy Master) conducted a review of the caselaw. He quoted HHJ Collender in Douglas v O’Neill [2011] EWHC 601, noting that “surveillance evidence has long been a legitimate weapon, when properly obtained and legitimately used, for a defendant to put before a court that may demonstrate that a claimant’s evidence is false”. While highlighting the court’s power to exclude evidence under CPR 32.1, he also recalled Potter LJ’s finding in Roll v Hume [2001] EWCA Civ 146that the starting point should be to admit potentially damaging surveillance evidence and allow cross-examination on it – provided that this would not amount to “trial by ambush”.

Importantly, HHJ Grimshaw noted both the value and limitations of surveillance evidence. He agreed with HHJ Ambrose’s proposition in Cullen v Henniker-Major [2024] EWHC 2809 (KB):

… I accept that if something is shown on the footage, that is determinative of it happening. However, I do not accept that the absence of something on the footage is determinative of it not happening.

Cullen v Henniker-Major [2024] EWHC 2809 (KB)

HHJ Grimshaw added emphasis, considering that particular caution had to be taken where footage appeared incomplete, acknowledging that surveillance footage shows “a snapshot in time” and that it may not reflect variations in an individual’s condition over “a day, week, month, or year”.

There were clear and acknowledged issues with the surveillance evidence. Footage had been omitted from the edited compilation served. Some audible commentary from the operatives had been removed. These omissions were not acknowledged in witness statements signed by employees of the surveillance company. HHJ Grimshaw did not accept the Claimant’s assertion, however, that the editing was prejudicial. Indeed, after reviewing the unedited video, he considered that the removed footage was either neutral or assisted the Defendant.

Ultimately, HHJ Grimshaw dismissed the assertion that the surveillance company “were part of a deliberate and dishonest attempt to provide a misleading picture of the Claimant’s (dis)abilities”. He found it likely that the operatives did a “poor job at editing as a result of poor execution of their work, rather than having malign or conspiratorial intent”. On a similar note, he was somewhat critical of the Claimant’s representatives in that “every little perceived issue with the surveillance evidence is seen through a lens of conspiracy”.

The judgment also considered the case of Jones v University of Warwick [2003] EWCA Civ 151. In Jones, the Defendant’s surveillance operative was acknowledged to have been dishonest – illegally entering the Claimant’s home while posing as a market researcher and covertly filming her. Lord Woolf nonetheless permitted the Defendant to rely on the surveillance evidence, finding that it was “not a case where the conduct of the defendant’s insurers is so outrageous that the defence should be struck out”, and that it “would be artificial and undesirable for the actual evidence, which [was] relevant and admissible, not to be placed before the [trial] judge”. HHJ Grimshaw reached the same conclusion in Perrin, stressing the “interest in the trial judge having all probative material before them to be able to reach a properly balanced decision”. He considered that it would be “manifestly unfair to the Defendant” to deprive her of the opportunity to put relevant surveillance evidence before the trial judge. The Defendant’s application was allowed.

Comment

The judgment in Perrin contains a useful recapitulation and application of the law on the admissibility of surveillance evidence. It also provides a number of useful points for practice.

While highlighting the limitations of surveillance evidence, HHJ Grimshaw ultimately concluded that the potential probative value of the footage outweighed the criticisms of its production.  This included, for instance, the suggestion that footage of the Claimant using her car gainsaid her assertion to an expert that she was no longer able to drive. A wide assertion is more easily contradicted by the “snapshot in time” captured on film.

The issues with the surveillance evidence – particularly in its editing – were mitigated by the retention of the full, unedited footage. HHJ Grimshaw was able to review the totality of the material and, ultimately, dismiss the Claimant’s suggestion that the editing had had a “malign motive” prejudicial to the Claimant. He also found “unrealistic” the Claimant’s solicitor’s suggestion that surveillance should be constant (§56).

Contrary to the Claimant’s submissions, HHJ Grimshaw also raised no issue with the surveillance company’s non-retention of the SD cards on which the original footage was stored. He accepted evidence that the company had an appropriate system in place for footage to be uploaded and backed up securely – and that it would be an insurmountable hurdle for a Defendant to definitively prove that no additional footage existed.

With permission granted for the Defendant to rely on the footage, the Claimant will have the opportunity to file evidence explaining its content. Both parties’ experts will also be able to review their conclusions. Those experts and the court are or should be, in HHJ Grimshaw’s view, “astute at understanding the limitations of surveillance evidence”. He has avoided an impossible situation where evidence with probative value, seen by the parties and Counsel, is not made available to the trial judge – surely contrary to the interests of justice in all but the most extreme circumstances.

Daniel Millar, pupil barrister

• Charlotte Reynolds of 12KBW acted for the defendant in Perrin v Walsh.