During a medical malpractice jury trial, the defendant physicians sought leave under Rule 53.08 to file a supplementary expert report and to elicit testimony from their experts on matters not explicitly stated in their reports.
The court denied leave for the supplementary report, finding it failed to comply with Rule 53.03 by omitting the reasons for its conclusions, and its admission would cause undue prejudice to the plaintiffs.
The court also ruled on several evidentiary objections, narrowly interpreting the 'latency' principle.
The court held that experts cannot use conclusory statements in their reports to ambush opposing parties with new reasons or theories at trial, though exceptions were made where testimony directly responded to new developments during the trial.
