Liability to the claimant for her personal injury claim was admitted, but quantum was disputed. The defendant's expert suggested in May 2015 that the claimant was exaggerating her continuing symptoms. However, instructions were given to a surveillance company only in February 2016, shortly before trial. The defendant applied for permission to rely on the surveillance video when it was received, and the judge held that as a result the trial date would have to be vacated.

As to the application, the judge noted that it is generally in the interests of justice to allow the defendant to cross-examine a claimant on video evidence which may undermine the claimant's case, provided that that does not amount to "trial by ambush". Foskett J agreed with earlier caselaw that an "ambush" means where a claimant has not had a fair opportunity to deal with the evidence (and so there is no need to find some sinister motive on the part of the defendant, ie to deliberately wrong-foot the claimant at the last minute).

The judge made a general observation that "more liberal use" should be made by the courts at the case management stage of orders requiring the application by a defendant to rely on surveillance evidence by a certain specified date (in situations where the claimant perceives a risk of this kind of evidence being relied on (especially if medical advisers have expressed reservations about the claimant's symptoms)). The judge also noted that "A very significant factor in deciding whether to accede to a late application, in my judgment, is the time when a defendant ought reasonably to commission such evidence. Once the claimant's case, both in relation to the disabilities relied upon and their consequences, is clearly articulated and the defendant is possessed of an opinion from an expert upon whom it relies that the claim is "suspect", it seems to me that the obligation actively to obtain surveillance evidence arises if it is considered a proportionate approach to adopt in the particular case. The longer it is left and the nearer the time gets to trial, the more likely it is that the court will regard the delay as culpable".

On the facts of this case, the judge was critical of the defendant's delay in obtaining the surveillance evidence but "with considerable misgivings", he granted permission for it to be received at trial, in the overall interests of justice. The defendant should be responsible, though, for the additional costs of instructing the claimant's experts to consider the new material and for those experts to discuss it with their counterparts in order to make a new joint statement.