If a document signifying any consent which is required by this Part to be given is witnessed in accordance with rules, it is to be admissible in evidence without further proof of the signature of the person by whom it was executed.
A document signifying any such consent which purports to be witnessed in accordance with rules is to be presumed to be so witnessed, and to have been executed and witnessed on the date and at the place specified in the document, unless the contrary is proved.