The Plaintiffs alleged that mineral leases held by the Defendants had terminated due to lack of production. The Parties entered into a litigation plan that set timelines for the delivery of primary expert reports, rebuttal expert reports and surrebuttal expert reports. The Plaintiffs served expert reports on the Defendants, and one Defendant served a rebuttal report on the Plaintiffs. Shortly before Trial began, counsel for the Defendant Nexen advised the Plaintiffs that it intended to object to the admission of certain portions of the Plaintiffs’ expert reports. The afternoon before the Trial commenced, the Plaintiffs advised the Defendants that it would not call certain expert witnesses at Trial, and would be deleting portions of another of its expert reports. The letter stated that the Plaintiffs would proceed on the basis that Nexen would not call rebuttal expert evidence at Trial.

Counsel for the Defendants alerted the Court to this issue in opening statements and advised the Court that they would call expert witnesses during the Trial. Just prior to the closing of the Plaintiffs’ case, counsel for the Plaintiffs advised the Defendants that they would object to the Defendants calling any expert evidence. The Defendants applied for a direction that their expert evidence was admissible. The Plaintiffs argued that the Defendants did not submit primary expert reports as provided for in the litigation plan and under the Rules of Court. Further, since the Plaintiffs called only limited expert evidence at Trial, there was nothing to rebut. It would be an abuse of process to allow the Defendants to call rebuttal experts after the close of the Plaintiffs’ case.

Rule 5.36 requires the Party receiving an expert report to provide reasonable notice of any objection regarding the admissibility of the report at Trial. Romaine J. held that notice the day before Trial or during the course of Trial was not reasonable. Romaine J. further held that even if the Defendants were in error in failing to file primary expert reports, there was no doubt that the Defendants’ expert evidence was relevant. Excluding it for a technical failure to comply with a procedural Rule would be unjustified in the circumstances. Romaine J. held that a flexible approach to rebuttal reports has been adopted in Rule 5.35, which provides that a rebuttal report may include issues not raised in the initial expert report. Romaine J. held that while the Plaintiffs were entitled to put in their case the way they wished, they were not entitled to rely on a technical objection to deprive the Defendants of the opportunity to present their case, particularly in the absence of any real prejudice.

 The Plaintiffs then applied to call their experts in rebuttal to the Defendants’ case, or to re-open the case to call their experts. Rule 9.13 provides that at any time before a Judgment is entered, the Court may hear more evidence if it is satisfied that there is good reason to do so. Romaine J. held that there was little prejudice to the Defendants in allowing the Plaintiffs to re-open their case because the Plaintiffs’ Application was brought before the Defendants led any evidence. Romaine J. further held that allowing the Plaintiffs to re-open their case to call expert evidence that was previously disclosed to the Defendants did not give the Plaintiffs the opportunity to re-argue their case. In this context, Romaine J. allowed the Plaintiffs to re-open their case to the limited extent of calling the experts whose reports had been previously disclosed to the Defendants.