What is the legal burden of proving that a will was duly executed?

The parties agree on the applicable law. In Vout v. Hay, 1995 CanLII 105 (SCC), [1995] 2 S.C.R. 876, Sopinka J. outlined the legal burdens as follows at para. 26: Although the propounder of the will has the legal burden with respect to due execution, knowledge and approval, and testamentary capacity, the propounder is aided by a rebuttable presumption. Upon proof that the will was duly executed with the requisite formalities, after having been read over to or by a testator who appeared to understand it, it will generally be presumed that the testator knew and approved of the contents and had the necessary testamentary capacity.