The rescission of an agreement altering the original obligation of a debtor or impairing the remedy of a creditor does not restore the liability of a guarantor who has been exonerated by such agreement.
Rescission Of Alteration -- Liability Not Restored
Mont. Code Ann. § 28-11-212, under Guaranty -- Liability and Exoneration of Guarantor.
Mont. Code Ann. § 28-11-212