A principal is bound by acts of the principal's agent under a merely ostensible authority to those persons only who have in good faith and without ordinary negligence incurred a liability or parted with value upon the faith of the authority.
Extent To Which Principal Bound By Acts Under Ostensible Authority
Mont. Code Ann. § 28-10-606, under Rights and Liabilities of Principal.
Mont. Code Ann. § 28-10-606