Expert opinions may be critical not only during the trial of an action, but also in connection with summary judgment motions that may follow the completion of discovery and the filing of the note of issue. Sometimes these motions may resolve issues of liability as a matter of law prior to trial. Whether a party is moving for summary judgment on the issue of liability or opposing such a motion, the submission of an expert affidavit may be of utmost importance.
In offering opinions in support of or in opposition to post note of issue summary judgment motions, an expert must rely in large measure upon evidence exchanged during pretrial discovery. One party to the litigation, more frequently the defendant, may have exclusive knowledge of some of the circumstances surrounding the occurrence, whether it is the condition of the premises, vital records, the identity of witnesses or possession of post-accident photographs of instrumentalities under its control. This evidence may be important to the resolution of the litigation and significant to the expert in formulating an opinion, whether it is the expert retained by the party possessing the information or an adverse party. It is prejudicial for an expert to rely upon evidence that has not been previously exchanged with all parties.
