Mont. Code Ann. § 1-5-624

Failure by a notarial officer to perform a duty or meet a requirement specified in this part, except failure to comply with the provisions of 1-5-603 (12) or 1-5-625 (1)(a) through (1)(d) and (2), does not invalidate a notarial act performed by the notarial officer. The validity of a notarial act under this part does not prevent an aggrieved person from seeking to invalidate the record or transaction that is the subject of the notarial act or from seeking other remedies based on the laws of this state, other than this part, or the laws of the United States. This section does not validate a purported notarial act performed by an individual who does not have the authority to perform notarial acts.