Can contracting parties vary or rescind the contract after crystallisation, or lay down their own crystallisation test?
parties may amend or terminate the contract at any time, but where, by doing so, they cause loss to the third party who has incurred expenses or undertaken an obligation in the expectation that the contract would be performed, the third party may recover the loss from any party to the contract who knew or ought to have known that the expenses would be or had been incurred or that the obligation would be or had been undertaken (s4(3)): except expenses incurred or obligation undertaken before the commencement of the provision (s4(4))
