In professional negligence claims against solicitors, each discrete head of damage must be independently established as involving a loss caused by the negligence — proof that some loss was caused does not suffice to establish all claimed heads. Where the counterfactual involves a hypothetical valid agreement, the court must assess what that agreement would actually have provided based on all available evidence, not merely the most favourable interpretation for the plaintiff. Legal costs incurred in litigation are not recoverable as damages for negligence where the plaintiff fails to establish that equal or greater costs would not have been incurred absent the negligent error. A modest discount for the contingency that a valid agreement might have been set aside on other grounds is appropriate where the probability is not so low as to be speculative.
The full text is available to signed-in members, including the 7 later cases that cite this judgment.