Credibility: A divisible concept?

March 31, 2022

Alice Dobbie

Alice Dobbie considers how credibility was approached by the courts in two recent cases: Cojanu v Essex Partnership University NHS Trust [2022] EWHC 197 and Palmer v Mantas and LV Insurance [2022] EWHC 90.


Claimants may be credible on some issues even where they have lacked credibility (to the point of dishonesty) on others. Dishonesty in relation to collateral issues should not be treated as relevant to credibility on central issues, and nor should it result in a fundamental dishonesty finding. Additionally, credibility is not necessarily impaired by social media posts which present a misleading (or ‘glossy’) narrative of a claimant’s lifestyle.

Cojanu v Essex

The facts

The claimant brought a claim in clinical negligence. He had been admitted to prison with deep cuts to his fingers. The defendant had negligently delayed surgery which had led to preventable, permanent damage to the fingers.

The claimant’s witness statement asserted that his cuts had been caused when defending himself from a knife attack by his wife. He maintained this account in oral evidence. In fact (provable through Crown Court records), the claimant had stabbed his wife twice in the chest and once in the back whilst their three children were present. He had suffered the cuts to his fingers in the course of resisting arrest following this attack. He had been convicted of attempted murder and imprisoned.

The defendant alleged that dishonesty in the mechanism of the injury was sufficiently central to the trial issues to require a finding of fundamental dishonesty.

The decision

At first instance, the lower court concluded that the claimant’s lies about the cause of his injuries amounted to fundamental dishonesty. However, the appellate court disagreed. It found that the cause of the cut fingers had no relevance to the clinical negligence and therefore the mechanism of the injury was incidental, not fundamental, to the claim. The finding of fundamental dishonesty was therefore overturned.

Application to assessments of credibility

Credibility, it seems, is to be treated as a divisible rather than indivisible concept. Dishonesty on one issue does not preclude credibility on other issues.

However, the court in Cojanu recognised that judges are still entitled to be more wary of accepting evidence where the witness has lied about other issues.

This means that Cojanu is best understood as a general defence of the right to sue for negligence and as a call to assess each part of a case on its own merits. Defendants should rightly be wary of branding claimants liars when the true picture is more nuanced. But the decision is not support for the proposition that credibility is invariably mixed. It remains the case that serious lies about incidental matters should be red flags to a defendant when considering a claimant’s credibility on other triable issues.

Palmer v Mantas

The facts

The claimant brought a claim for a subtle brain injury arising out of a road traffic accident. The claim was pleaded at £2.2m. Liability was admitted. The defence was that the true value of the damages was modest and the claimant had dishonestly exaggerated her case. Surveillance evidence was neutral and so extensive social media posts which appeared to contradict the claimant’s account of a restricted lifestyle took on particular importance.

The decision

The High Court accepted the claimant’s explanation that the social media posts were putting a gloss on her life and were not reflective of reality. In finding that there was nothing sinister in the difference between the claimant’s account of debilitating injuries and the divergent social media posts, the Judge placed particular weight on the views of the medical experts on conscious and unconscious exaggeration. They were almost all satisfied that any exaggeration, if present, was unconscious. Accordingly, the Judge approached the significance of the contents of social media posts with caution. His conclusion was guarded, but sufficient for the claimant to succeed: the posts were “not incompatible” with the claimant’s experience of troubling symptoms.

Application to assessments of credibility

Social media and ‘deep’ internet searches have become a useful weapon in a defendant’s armoury and defendants should continue to make use of them. However, allowance must be made for the nature of social media which can include a deliberate intention to peddle a lifestyle narrative which is not accurate. Where a credible explanation of ‘glossy’ posting explains differences between online and real life impressions, the social media posts are unlikely to impair a claimant’s credibility.

As ever, social media evidence should always be available to medicolegal experts and they should be asked to comment specifically on conscious and unconscious exaggeration. For a fuller consideration of exaggeration, see this article.

Alice Dobbie is a member of the Personal Injury: Defence team at Exchange Chambers. She acts exclusively for Defendants. She is a specialist in civil fraud, negligence and costs.