Home Knowledge Expert Exposure: Protecting Privilege in Expert Evidence

Expert Exposure: Protecting Privilege in Expert Evidence


Recently the Court of Appeal in Sweeney v The Voluntary Health Insurance Board IECA 150 considered the position of a proposed expert witness for the plaintiffs who was already retained by the defendant in two other non-related actions.  The decision raises interesting questions about conflict of interests for expert witnesses and exposure of experts to privileged information by the party that retains them. 

This ongoing legal dispute involves the building of a private hospital in Limerick and the plaintiffs allege, among other allegations, a breach of dominant position under competition law by the VHI in their refusal to approve the hospital and provide insurance cover.

VHI Seeks to Exclude the Expert

The plaintiffs had sought to introduce expert evidence by Professor McDowell and VHI applied to exclude his evidence on the basis that as he had been retained by them in other non-related but similar litigation. He had sight of privileged and commercially confidential information and there was a risk that information could be disclosed in these proceedings.  

Expert Duties

We have previously discussed the duties of expert witnesses here. In this instance Professor McDowell gave sworn evidence that he was fully cognisant of his duties as an independent expert. In particular he stated that he did not retain hard or electronic copies of the material provided to him on behalf of the VHI in the two other cases and that he did not rely on any information provided to him by on behalf of the VHI, confidential or otherwise, in the preparation of the draft report which he provided to the plaintiffs. 

The VHI did not suggest any intentional misuse of information, rather it was that the Professor could not “unknow” the privileged and confidential information or prevent its inadvertent disclosure in the proceedings. 

In the High Court Barrett J. refused VHI’s application to exclude the Professor’s evidence and this decision was appealed to the Court of Appeal.  Barrett J. held that the applicable test in the circumstances was: “whether it is likely that would be unable to avoid having recourse to privileged material” previously provided to him by the VHI.”  The High Court considered that such avoidance in this case was “possible”.

Collins J. overturned the decision and held that the High Court had been wrong in what test should apply in this sort of application. In a lengthy decision the Court of Appeal engaged significantly with the legal authorities and the facts that had been put before the Court.

The Court of Appeal was also cognisant of the constitutional rights at play in this case. On one hand was the entitlement of any party involved in litigation to select and engage the expert of its choice. The Court also acknowledged that the VHI also had a significant interest in the protection of its confidential and/or privileged material and that the protection of such material from unauthorised disclosure goes beyond a mere rule of evidence, legal profession privilege being a fundamental condition on which the administration of justice rests and therefore having constitutional status.

“One size Fits All” Test Not Appropriate

In relation to this particular expert the Court of Appeal considered he had a significant level of engagement with the VHI including:

  • attending consultations with the VHI and its legal representatives – in person and on the phone;
  • producing written memoranda addressing issues of dominance; and
  • invoicing for 80 hours of work between July 2010 and May 2011 on one case

The VHI argued that given the “ pivotal role” played by expert economic witnesses in competition law claims, it should not have to demonstrate a likelihood – in the sense of a probability – of its privileged and confidential information being used but that any appreciable risk was sufficient to warrant the Court’s intervention.

Collins J. highlighted the fact that there are many different types of experts and that some do not need to be provided with confidential or even privileged material in order to fulfil their role. Whereas others will require significant levels of privileged and/or confidential information and may have much greater involvement in the strategic decision-making in litigation.  Collins J. considered that given the many different types of experts and their differing levels of involvement in case preparation a “ one size fits all” approach –  treating all expert witnesses as if they were in the same position and not having careful regard to their actual role in the litigation – was not appropriate.

What is the Test to Protect Privilege from Disclosure by Experts?

Collins J. held that to require a party to establish as a matter of likelihood (in the sense of probability) that, absent court intervention, its privileged and/or confidential information will be disclosed in the future creates a significant obstacle to the protection of such information. He noted that while there may be cases where a likelihood of disclosure can be demonstrated and/or inferred, there will be cases – perhaps many cases – where such a threshold is practically insurmountable. He held that the threshold is whether there is, on the evidence, a real risk (as opposed to a likelihood) of disclosure. 

The Court of Appeal held that in this case there was an obvious risk of disclosure. Collins J. stressed that this risk was of an unconscious and/or inadvertent disclosure by Professor McDowell and there was no implication that he would intentionally act to breach his duties.  The risk of unconscious and/or inadvertent disclosure and/or reliance was a very real and obvious risk in this case.

Expert Duty to Assist the Court?

Finally, the Court of Appeal noted the principles developed in cases such as The Ikarian Reefer 2 Lloyds Rep 68 to be very valuable and are reflected in Order 39, Rule 57(1) of the Rules of the Superior Courts. However, the fact that an expert witness has an overriding duty to assist the court did not involve the abrogation of a client’s entitlement to protect confidential and – especially – privileged information provided to an expert in the course of their retainer.  Collins J. was clear in holding that an expert cannot be compelled to disclose privileged information. 

Conflict of Interest

The Court of Appeal held that by agreeing to act for the plaintiffs in these proceedings, this expert had put himself into a position of obvious conflict of interest which was only belatedly recognised before the Court.

Key Takeaways

We have previously considered issues of protecting privileged information during the course of litigation (see here).  This recent decision serves as a reminder to parties in litigation to be careful in choosing their expert witness.  Parties to litigation, especially instructing solicitors, should always be alive to duties of experts, especially conflicts of interest. While there is no monopoly on the use of experts, if there is a real risk of disclosure of privileged or confidential information the courts may prevent their evidence from being used at trial. 


Contributed by Catherine Thuillier