In Shallow v. Follwell, 2017 WL 4638078, the Missouri Court of Appeals for the Eastern District, Division Four, held that the trial court abused its discretion by permitting the “unfairly cumulative and prejudicial repetition of expert opinions from [defense] expert witnesses.” The abuse of discretion standard holds that a trial court abuses its discretion “when its ruling is clearly against the logic of the circumstances then before the court and is so unreasonably and arbitrary that it shocks the sense of justice and indicates a lack of careful, deliberate consideration.” This is a highly deferential standard which finds that if “reasonable persons can differ as to the propriety of the court’s action, then it cannot be said that the court abused its discretion.” Nevertheless, the Court of Appeals found that the trial court “abused its discretion in this case by allowing the serial repetition by the defense experts of their opinions regarding the critical issues in the case.” However, the Court held that it was not drawing a bright line rule as to how many experts may be allowed to testify in a given case.
The trial court had held that this theory of causation implicated multiple areas of medical expertise and thus it was proper for each expert to testify. The trial court found that each of the experts had a different specialty and “gave their own parts.” However, the Court of Appeals found that in actuality, each witness testified not only to their own specialty but to the sum and substance of the defense’s theory of the case. “The problem with the trial court’s handling of the scope of the defense experts’ testimony is that all of them were permitted to not only provide opinions addressing the portion of the defense theory which touched on their specifically-endorsed expertise but they were then allowed to offer a chorus of the same ultimate opinions…” The Court found that it was an abuse of discretion to allow such cumulative evidence to enter into evidence.”
This is an unprecedented decision. Missouri Courts have long held that the admission of cumulative evidence is within the discretion of the trial court. See State v. Green, 603 S.W.2d 50 (Mo. App. 1980) (holding that the trial court did not abuse its discretion in allowing a video to be shown at trial three times even though it was cumulative). To avoid a similar outcome as occurred in this case, parties should take care to ensure that defense experts stick to their specific specialty, as the Court hinted that this might have changed the outcome of the case had experts not all testified to the overall defense theory. However, this is difficult given the nature of expert witness testimony. It should be noted that none of the cases cited to by the Court of Appeals hold that admitting cumulative evidence constitutes reversible error, especially under an abuse of discretion standard.