Haithwaite v Thomson Snell & Passmore (A Firm)

Where solicitors’ negligence causes a claimant to lose the opportunity to pursue a claim, damages are assessed by valuing the lost chance, not by treating the underlying claim as if it had certainly succeeded. The court should ordinarily assess the prospects of success on the available evidence and should not definitively determine issues which would have required trial in the lost action. A claim must have had a real and substantial prospect of success. The court may make a broad and generous assessment, while allowing for litigation risks. Causation requires a realistic assessment of whether the lost action would probably have established actionable harm. Where pre-existing injury is exacerbated by the negligent delay, the claimant may recover for the additional loss attributable to that exacerbation.

The claimant sued his former solicitors for negligence after they failed to serve proceedings against a National Health Service Trust within time. Liability for that negligence was admitted. The lost proceedings alleged that doctors had negligently failed to investigate and treat a developing subdural haematoma. The central issues were whether the claimant would probably have established negligence against one or more doctors, whether that negligence would have caused more than minimal additional loss, and what damages he would have recovered. The court therefore assessed the value of the lost litigation, including general damages, earnings, care and future losses.

1. Lost chance. The claimant’s task was to establish that the lost claim had a real and substantial, rather than negligible, prospect of success. The court applied the principles in Mount v Baker Austin (a firm) [1998] PNLR 493, including the need for a realistic assessment and a generally generous approach where the solicitors’ negligence caused the evidential difficulty.
2. The court should normally investigate prospects rather than decide definitively how the underlying action would have been determined. That approach was supported by Hanif v Middleweeks (a firm) [2000] Lloyd’s Rep. P.N. 920 and Dixon v Clement Jones solicitors (a firm) [2005] PNLR 6. The present case did not fall within the rare category where the lost claim could confidently be treated as worthless.
3. Applying Bolam v Friern Hospital Management Committee [1957] 1 WLR 582, the claimant faced substantial uncertainty in proving that either doctor’s conduct fell outside the practice accepted by a responsible body of medical opinion. The court assessed the prospects of establishing negligence at 40 per cent.
4. On causation, the court applied the ordinary but-for approach. If negligence had been established, there was a strong prospect that a scan and timely treatment or monitoring would have occurred. The medical evidence gave the claimant a 75 per cent prospect of proving more-than-minimal additional harm, producing an overall 30 per cent prospect of establishing liability.
5. The court assessed the likely underlying damages at £392,336.44 including interest, and awarded 30 per cent of that sum: £117,700.93. The assessment included damages for exacerbation of pre-existing brain injury, consistent with the eggshell skull principle, and a Smith v Manchester award where there was a substantial risk of future disadvantage on the labour market.

First-instance decision. Judgment entered for the claimant in the sum of £117,700.93.