What is the legal burden of proving the validity of a Power of Attorney and Codicil?

The respondents, as the propounders of the Codicil and Power of Attorney, bear the onus of proving the validity of those documents. Given that both documents appear to meet the requisite formalities, which was not contested, the presumption of validity in Vout v. Hay, supra, applies. If there is evidence which, if accepted, would tend to negative the existence of the Deceased’s capacity, suspicious circumstances are present, the presumption of validity is rebutted, and the respondents would reassume the legal burden of establishing capacity.