What is the evidentiary burden of making a will in circumstances where the testator has been found not to have understood the will?

In Vout v. Hay, 1995 CanLii 105 SCC, Sopenka J. speaking for the court, outlined the evidentiary burden when suspicious circumstances exist. The court noted two incidents of suspicious circumstances at paragraph 25 and stated, “The suspicious circumstances may be raised by (1) circumstances surrounding the preparation of the will, (2) circumstances tending to call into question the capacity of the testator…” Sopinka J. continued at paragraph 26, The burden with respect to testamentary capacity will be affected as well if the circumstances reflect on the mental capacity of the testator to make a will. 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 being read over to or by the 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.