(1)  Prerequisites for a decision that a breach of duty caused particular harm are as follows:

(a) the breach of duty was a necessary element of the occurrence of the harm ( "factual causation" );

(b) it is appropriate for the scope of the liability of the person in breach to extend to the harm so caused ( "scope of liability" ).

(2)  In deciding in an exceptional case, in accordance with established principles, whether a breach of duty, being a breach of duty that is established but which can not be established as satisfying subsection (1)(a) , should be taken as satisfying subsection (1)(a) , the court is to consider (among other relevant things) whether or not and why responsibility for the harm should be imposed on the party in breach.

(3)  If it is relevant to deciding factual causation to decide what the person who suffered harm would have done if the person who was in breach of the duty had not been so in breach –

(a) the matter is to be decided subjectively in the light of all relevant circumstances, subject to paragraph (b) ; and

(b) any statement made by the person after suffering the harm about what he or she would have done is inadmissible except to the extent (if any) that the statement is against his or her interest.

(4)  For the purpose of deciding the scope of liability, the court is to consider (among other relevant things) whether or not and why responsibility for the harm should be imposed on the party who was in breach of the duty.