In a complaint alleging negligent medical care, an expert witness testified at trial that there was a lack of supervision of defendant's residents. This new testimony was not disclosed in plaintiff's Rule 213 answers or responses. The court ordered a mistrial because the undisclosed opinions by the expert would affect the outcome of the trial because defendant was surprised and prejudiced by the testimony. The court stated that the "Illinois Supreme Court rules on discovery are mandatory rules of procedure subject to strict compliance by the parties." However, the remedies available for violations of Rule 213 violations are within the circuit court's discretion. When the violation is of such character and magnitude to deprive a party of a fair trial and the party seeking a mistrial demonstrates actual prejudice, a mistrial is warranted. Clayton v. County of Cook, No. 1-02-1009, 2003 Ill.App. LEXIS 1427 (1st Dist. Dec. 11, 2003).
