The better practice would have been to vacate the decision of the Court of Appeals and to remand the case to the circuit court with instructions to vacate the judgment. In that case, however, there was no harm in merely dismissing the appeal, because it appears that there were no potential future consequences arising from the continued existence of the circuit court's judgment. By contrast, in Kay , which challenged a plan to include a formal prayer at a high school graduation ceremony, the court determined that the case became moot when the graduation ceremony took place. The court reversed the decision of the Court of Appeals on the merits, but it also remanded the case to the circuit court with instructions to vacate the judgment. On reflection, we hold that the better practice when a case becomes moot on appeal or on review is to vacate both the decision of the Court of Appeals and the circuit court judgment.
Reversal implies that a court incorrectly decided the case on the merits.
After determining that the case was moot, the Court of Appeals dismissed Nimbus's appeal. Although dismissal of an appeal does not necessarily result in an affirmance of the judgment being appealed, dismissal of an appeal unquestionably leaves the judgment in place. The judgment disposing of Nimbus's third-party claims against National was a disposition on the merits of those claims. Under familiar principles of claim preclusion, if the judgment were left in place, the judgment might preclude Nimbus from asserting its claims against National in a new action. Therefore, rather than merely dismissing the appeal, the Court of Appeals also should have vacated the judgment disposing of the third-party claims and remanded with instructions to dismiss those claims as moot.