A trial court has “considerable discretion” regarding the admission or exclusion of evidence. Lozano v. BNSF Ry. Co., 421 S.W.3d 448, 451 (Mo. 2014). An appellate court will typically only overrule a decision on the admission or exclusion of evidence if it is a clear abuse of discretion. The error must “materially affect” the merits of the action. Id. at 451-52.
Certain evidence decisions, however, may not be subject to an abuse of discretion standard. For instance, physicians are prohibited from testifying in violation of the physician-patient privilege and attorneys are prohibited from testifying in violation of the attorney-client privilege. See Section 491.060, RSMo. Because these are statutory privileges, their application may be subject to a de novo review. See Bey v. Precythe, 586 S.W.3d 781, 784 (Mo. Ct. App 2019) (“[s]tatutory interpretation raises a question of law that we review de novo”). With a de novo review, the appellate court is not bound by the legal determinations made by the trial court.