In trials in Missouri, the Court has “considerable discretion” in the admission or exclusion of evidence, and, absent clear abuse of discretion, its actions will not be grounds for reversal. Cox v. Kansas City Chiefs Football Club, Inc., 473 S.W.3d 107, 114 (Mo. 2015). An abuse of discretion occurs if the decision is “clearly against the logic of the circumstances…so unreasonable and arbitrary that it shocks the sense of justice and indicates a lack of careful, deliberate consideration.” Id.
Importantly, a judgment will not be reversed on appeal for the improper inclusion/exclusion of evidence unless it “materially affected the merits of the action.” Id. In other words, it must be “outcome-determinative.” Williams v. Trans States Airlines, 281 S.W.3d 854, 872 (Mo. Ct. App. 2009).