What is the legal burden of establishing due execution of a codicil?

It is established law that the propounder of a will (or as in this case, a codicil) bears the legal burden of establishing due execution of the will, knowledge and approval of the will by the testator, and the capacity of the testator. The propounder of the will is aided by a rebuttable presumption that where the will was duly executed after having been read over by the testator who appeared to understand it, he or she knew and approved of the contents and had the necessary capacity to execute it (Vout v. Hay, 1995 CanLII 105 (SCC), [1995] 2 S.C.R. 876, paragraph 26 (“Vout v. Hay”).

Where suspicious circumstances are present on a balance of probabilities, including with respect to the testator’s mental capacity, the presumption is rebutted and the propounder of the will reassumes the legal burden of establishing its validity. Suspicious circumstances can be established by producing evidence which, if accepted, would tend to negative the existence of the testator’s capacity (Vout v. Hay, supra, paragraph 27).