Concern about the quality, and the cost, of some expert evidence in court cases is long-standing, particularly when it comes to personal injury cases.
The Law Reform Commission (LRC), having published a consultation paper on the issue in 2008, published a Report on Consolidation and Reform of Aspects of the Law of Evidence in 2017 which recommended, to avoid experts being seen as the “hired gun” of the party who engaged them, their main duties should be set out in legislation.
These included an overriding duty to the court to provide truthful, impartial and objective evidence; to state the facts and assumptions and any underlying scientific methodology on which their evidence was based and to confine their evidence to matters within the scope of their expertise.
The recommended legislation was not forthcoming but new rules of court introduced a year earlier had put the duties of experts on a more formal footing, including a duty to assist the court concerning matters within their field of expertise and to provide reports acknowledging that duty and disclosing any conflict of interest. The duty, the rules specified, overrides any obligation to any party paying the expert fees.
Parties were no longer permitted to call as many experts as they liked and the court could restrict expert evidence to whatever it considered was reasonably required to enable it decide the case.
Field of expertise
The 2016 rules introduced reforms aimed at focusing expert testimony with a consequent limitation on the associated costs. The court, for example, could order a single joint expert or require experts to meet and to produce joint expert reports. Parties might only call one expert in any particular field of expertise unless the court, for special reasons, permits more.
There is no general requirement under Irish law that expert evidence must meet any specific threshold of reliability before it is admissible but it may be challenged on grounds it lacks a reliable scientific or methodological foundation. Issues of reliability may affect the weight a court gives to expert evidence, even when admitted. The court is not required to accept expert evidence, even uncontradicted evidence, as only the court can resolve disputed issues of fact.
Senior Counsel Ronan Lupton, who was involved in an important case, Donegal Investment Group plc v Danbywiske, which considered how an appellate court should scrutinise findings made by a trial judge with the assistance of expert evidence, said he believed lawyers would welcome any further clarity concerning the use and admissibility of expert evidence.
While legislation in line with the recommendations of the LRC, would be “optimum”, a practice direction or additional court rules would “go a long way”, said Mr Lupton.