The Missouri Court of Appeals for the Western District recently confirmed the long-standing principle that a party’s failure to plead even a valid affirmative defense constitutes a waiver of that defense. Missouri trial courts have no authority to step in and remedy a defendant’s pleading error by applying such a defense sua sponte (“of its own accord”).

The case of Templeton v. Cambiano involved a series of three promissory notes issued between 2003 and 2005. The plaintiff claimed that the defendant had executed the notes in order to borrow nearly $50,000 but had then failed to make a single payment. She filed suit for the principal, plus over $75,000 in interest and late fees, in December 2015, which was just shy of ten years after the final note had been signed. The defendant filed a responsive pleading that generally denied liability for the debt, but his answer did not separately allege that the plaintiff had failed to mitigate her damages by allowing interest and late fees to accumulate for almost a decade before filing suit.

After a bench trial, the trial judge entered judgment in favor of the plaintiff, but excluded from the award all of the claimed interest and late fees, on the grounds that the plaintiff had “failed to mitigate these damages by the delay in prosecuting this action for ten years.” In her sole point on appeal, the plaintiff argued that the trial court had overstepped its authority by applying the affirmative defense of failure to mitigate damages, which the defendant had failed to plead.

The Western District Court of Appeals reversed the trial court’s judgment and remanded the case with orders to amend the judgment to include the $75,927.12 claimed as interest and late fees. This holding was based on long-standing Missouri precedent that an affirmative defense is waived if it is not either: (1) properly pleaded, according to Missouri’s fact-pleading standard, or (2) tried by the parties’ express or implied consent. Failure to mitigate damages is an affirmative defense. Seeing no evidence in the record that the issue of failure to mitigate damages had been tried by the parties’ consent, the appellate court ruled that the defendant had waived the defense when he omitted it from his answer. Regardless of how meritorious the defense might have been, the appellate court concluded, “the circuit court could not breath life back into this extinguished claim sua sponte.”

The defendant also argued that even if the trial court had relied on “a wrong or insufficient reason,” its judgment should still be affirmed because the equitable doctrine of laches would have supported the same result. Laches is an equitable doctrine that precludes claims asserted after an unreasonable delay, which has prejudiced the opposing party. The Court of Appeals was wholly unconvinced, observing that here too, Defendant had failed to raise laches as an affirmative defense. (Laches is specifically listed in Missouri Rule 55.08 as one of the affirmative defenses that must be pleaded to avoid waiver.) For good measure, the Court also concluded that in any event, the doctrine of laches would not apply even had it been properly pleaded.

The significance of this opinion for defendants in Missouri state court is twofold. First, the case stands as a potent reminder of the importance of carefully pleading all legal defenses and their supporting facts or, in the event a defense is omitted, of promptly seeking leave to amend the answer. Second, it demonstrates how a party’s failure to preserve its own legal defenses can tie the court’s hands, preventing it from crafting the remedy that it deems fair and leading to potentially severe results. Here, the pleading error was costly, ultimately increasing the defendant’s liability by about 150%.

The court of appeals opinion is available online through this link.