(1) Subject to this section, where the effect of a contract of insurance would, but for this section, be that the insurer may refuse to pay a claim, either in whole or in part, by reason of some act of the insured or of some other person, being an act that occurred after the contract was entered into but not being an act in respect of which subsection (2) applies, the insurer may not refuse to pay the claim by reason only of that act but the insurer's liability in respect of the claim is reduced by the amount that fairly represents the extent to which the insurer's interests were prejudiced as a result of that act.
(2) Subject to the succeeding provisions of this section, where the act could reasonably be regarded as being capable of causing or contributing to a loss in respect of which insurance cover is provided by the contract, the insurer may refuse to pay the claim.
(3) Where the insured proves that no part of the loss that gave rise to the claim was caused by the act, the insurer may not refuse to pay the claim by reason only of the act.
(4) Where the insured proves that some part of the loss that gave rise to the claim was not caused by the act, the insurer may not refuse to pay the claim, so far as it concerns that part of the loss, by reason only of the act.
(a) the act was necessary to protect the safety of a person or to preserve property; or
(b) it was not reasonably possible for the insured or other person not to do the act;
the insurer may not refuse to pay the claim by reason only of the act.
(6) A reference in this section to an act includes a reference to:
(a) an omission; and
(b) an act or omission that has the effect of altering the state or condition of the subject-matter of the contract or of allowing the state or condition of that subject-matter to alter.