Post-divorce proceeding; Dispute over the calculation of interest on a settlement agreement; Norman v. Norman; Laches; Attorney Gen. v. PowerPick Club; Contract interpretation; Klapp v. United Ins. Group Agency, Inc.; Laffin v. Laffin; Universal Underwriters Ins. Co. v. Kneeland; Brucker v. McKinlay Transp., Inc.

Holding that the trial court erred by denying plaintiff-ex-wife’s requested calculation of interest payments, the court vacated the ruling and remanded. The parties’ judgment of divorce contained a property settlement agreement, under which defendant-ex-husband was to pay plaintiff a certain sum of money over 12 years. After the final payment came due, she argued that he owed over $50,000 in accrued amortized interest. Defendant countered that a simple interest rate should apply and that he only owed $6,562.50 in interest. After an evidentiary hearing, the trial court applied defendant’s calculation of interest. On appeal, the court agreed with plaintiff that the trial court erred by sua sponte applying the defense of laches. “[B]ecause defendant never argued before the trial court that laches applied, [he] never established that he was prejudiced by plaintiff’s failure to ensure that [he] signed a mortgage note.” Rather, he “essentially argued that plaintiff’s calculation of interest was not consistent with the plain language of the agreement and that the trial court should therefore rely on defendant’s interest calculation.” It also agreed with plaintiff that the trial court erred by holding that it was required to apply defendant’s formula for calculating simple interest. “[C]ontrary to the trial court’s finding, both experts did not testify that it was ‘impossible’ to calculate the interest owed by defendant because a mortgage note was not executed.” Rather, plaintiff’s expert testified to the contrary. “Although the trial court as the finder of fact was permitted to conclude that [this] testimony was not credible or that it was proper to afford more weight to [defendant’s expert’s] testimony, there is no indication that” it did so. Rather, in its written opinion, it “found ‘both witnesses [to be] generally credible and unbiased.’” As such, the trial court “erred by finding that both experts concluded that it was ‘impossible’ to calculate interest without a mortgage note.” Finally, the court agreed with plaintiff that, even if a simple interest rate applied, the trial court erred by finding that she was only entitled to $6,562.50 in interest. “Because the record establishe[d] that the manner in which defendant calculated simple interest is not the proper way to calculate simple interest,” the trial court erred.