Historically, there has been some confusion over the exact interpretation of the disclosure rules. Previously, in Payne v Shovlin(1) both the High Court and the Supreme Court sought to clarify the position on precisely what obligation a party is under when it comes to the disclosure of evidence. However, the courts did not deal specifically with reports which were essentially critiques of the opposing parties' expert reports. More recently, the High Court was asked to clarify the position in relation to the disclosure of such expert commentaries.

In McHugh v O'Sullivan the defendant was sued for failure to diagnose a patella sleeve fracture of the plaintiff's knee during an arthroscopy procedure in July 2001. The case was listed for trial in July 2011. The plaintiff took the view that commentaries on the expert reports commissioned by the defendants for the purpose of assisting counsel in cross-examination were not disclosable under the relevant legislation. Despite the plaintiff disclosing the sought report, the defendant raised the issue of disclosure of such commentaries with Justice Irvine.

In her ruling, the judge stated that Statutory Instrument 391/1998 provides for a contemporaneous exchange of reports; therefore, expert commentaries on those reports should not be covered by the statutory instrument, except in circumstances where any expert making such commentary is proposing to give evidence over and beyond the evidence contained in the initial expert reports.

Based on this decision, experts can provide written commentary on an opposing party's expert report, without an obligation to disclose, as long as they are dealing simply with views expressed by the opposing expert and they are not extending or expanding the substance of their own evidence in any way. To comply with this ruling, experts must ensure that such commentaries are confined or else they will fall within the disclosure rules.

This article first appeared in the International Law Office Healthcare newsletter, 27 August 2014.