In re Meagher's Estate apparently establishes a new rule requiring that the contestant of a will on the ground of insane delusions must show that the delusion, exclusive of any rational motive, was the controlling cause in the disposition of the property.
John S. Calvert,
Washington Case Law,
Wills—Testamentary Capacity—Insane Delusions,
Wash. L. & Rev.
Available at: https://digitalcommons.law.uw.edu/wlr/vol38/iss2/24