Sylvia Betty Birch By Her Litigation Guardian Geoffrey Michael Birch and Douglas Birch

Sylvia Betty Birch, by her litigation guardian Geoffrey Michael Birch, sought special leave to appeal from a decision of the Court of Appeal. The dispute concerned the equitable doctrines of undue influence and mutual wills, particularly in the context of succession planning and the role of legal advisors. The applicant argued that the Court of Appeal had erred in its application of established legal principles regarding the burden of proof in undue influence cases, the relevance of familial relationships, and the effect of mutual wills.

The primary legal issues before the High Court were whether the Court of Appeal had correctly applied the principles concerning the burden of proof in undue influence claims, especially where the donor possesses full capacity. This included whether the Court of Appeal had wrongly suggested that a donor's capacity lightened the burden on the donee to demonstrate emancipation from influence. Further issues involved the correct approach to the relationship of love and affection between a donor and donee, and whether such a relationship should reinforce or rebut the presumption of undue influence. Finally, the Court was asked to consider the correct interpretation of the doctrine of mutual wills, specifically whether it created a bare trust that prevented the survivor from dealing with the property.

The applicant contended that the Court of Appeal had misapplied the principles from cases like *Watkins v Coombes* and *Johnson v Buttress*, by suggesting that a donor's capacity alone could significantly reduce the onus on the donee to prove the absence of undue influence. It was argued that the Court of Appeal's reasoning in relation to the mother-son relationship incorrectly treated it as a factor rebutting the presumption of undue influence, when it should have reinforced it, making it more difficult to disentangle the influence. Regarding mutual wills, the applicant argued that the Court of Appeal's finding that the survivor was unable to deal with the property was contrary to the principles established in *Birmingham v Renfrew*, which allows the survivor to enjoy the property subject to not defeating the testamentary intentions.

The respondent argued that the case was primarily one of fact and not appropriate for special leave. They contended that the Court of Appeal had correctly applied established principles, noting that the burden of proof in undue influence cases can vary depending on the specific facts. The respondent submitted that the Court of Appeal had considered all relevant factors, including the donor's full capacity, her long-held intentions, and the fact that she had received independent legal advice, which collectively discharged the burden of proof. Furthermore, the respondent argued that the Court of Appeal's interpretation of mutual wills was consistent with *Birmingham v Renfrew*, as the survivor's right to dispose of property is not unqualified and must not be exercised to defeat the mutual will agreement.