Next it is said on behalf of the widow that the antenuptial promise by the deceased to leave her £20 a week, though for lack of writing it was unenforceable at law, was enough to give her good prospects of success if she had applied under the Testator's Family Maintenance Act (S.A.) for additional provision out of the deceased's estate, and that in reliance upon the purported assignment as being effectual she abstain from taking any proceedings for an order under the Act. The learned judge evidentially accepted evidence that she gave to the effect that it was her belief in the efficacy of the assignment that led her to desist from making such an application; and on the footing that this was so an argument is submitted, expressed in terms of the estoppel, that the executors will not now be allowed to deny her title to the debt owed by the company.
45 This passage of Kitto J's judgment suggests that prospects of success, as opposed to a right simpliciter to make a claim, is a necessary aspect of a claim. It seems to me that in a proprietary estoppel claim, where the alleged detriment is the giving up or non-enforcement of a right in reliance on assurances, a plaintiff must establish more than the mere existence of a chance to exercise that right . It seems to me that it is necessary to prove to the requisite standard that if the right had been enforced instead of given up, there were prospects of doing better than that which was achieved in reliance upon the assurance. There has to be a "real chance" that the plaintiff would have been able to achieve a better outcome: Foran v Wight (1989) 168 CLR 385, per Deane J at 436. However I should qualify these conclusions by saying that much will depend upon the nature of the right and the circumstances of the particular case.
46 There is some evidence that the plaintiff may not have achieved a better outcome in the Family Court in the email from her solicitor, that suggested that even without the $50,000 payment the plaintiff was achieving a "good deal". There is no evidence as to the expertise or experience of the plaintiff's solicitor and there is also the problem of the generality of the expression, a "good deal". Such an expression does not necessarily translate into there being no chance of doing better, if the plaintiff had litigated her property claims. Whether the plaintiff acted to her detriment in giving up her right to have the Family Court determine her property rights on the merits cannot be ascertained in the circumstances of and on the evidence in the case. It is just not possible to know whether the plaintiff would have achieved a better outcome than she did achieve by negotiating with the deceased. Although the plaintiff gave up the opportunity I am not satisfied that it can be characterised as conduct to her detriment.
47 The next aspect of the conduct relied upon is the plaintiff's foregoing the $50,000 cash payment and agreeing for it to be used on the improvement of the Property. I am satisfied that at the time the deceased said he would agree to the Notation being included in the Consent Orders, the plaintiff relied upon the deceased's assurances that he would bequeath the Property to her and acted to her detriment in agreeing to the $50,000 being used on improvements to the Property. In those circumstances I am satisfied that it was unconscionable for the deceased not to honour his promise to the plaintiff to leave her the property in his Will.
Relief
48 In Vukic, Brereton J discussed whether relief in proprietary estoppel cases should be "based on the assumed or expected state of affairs which the defendant is estopped from denying [Commonwealth v Verwayen [1990] HCA 39; (1990) 170 CLR 394, 443 (Deane J)], or is limited to the minimum equity needed to avoid the relevant detriment". His Honour concluded that there is a "strong case in principle" that in a proprietary estoppel case (as distinct from a "windfall equity" case), the expectation basis of the equity favours the view that the prima facie entitlement is to satisfaction of the relevant expectation: at [33].
49 Such a remedy may be declined where it would be disproportionate; for example, a claimant who established a proprietary estoppel on the basis of his expenditure on improvements to the subject was refused relief because he enjoyed 18 years of rent-free accommodation: Sledmore v Dalby (1996) 72 P & CR 196 CA. It may also be declined where there are special circumstances; for example, in Giumelli v Giumelli (1999) 196 CLR 101, the plaintiff's younger brother who had done considerable work on the subject property, was awarded the alternative remedy of a a monetary sum.