Litigation - expert witnesses - proprietary methods

Mulcahy v Avoca Capital Holdings Ltd [2005] IEHC 136 (High Court)

The High Court has underlined that expert witnesses in litigation must be prepared to have their methodology and procedures examined in court. This is so even if the expert's methods are proprietary or otherwise are secret.

Expert witnesses perform an important role in litigation and in other formal dispute resolution procedures such as arbitration. A court can give special weight to the evidence and opinion of an expert witness, when that evidence or opinion is given in his or her field of expertise. Therefore, the courts ensure that the parties to litigation are able to test the expert's evidence as effectively as is reasonably possible.

Allegations and counter-allegations in this litigation regarding suggested improper uses of the company's IT facilities prompted Mr Mulcahy to seek a forensic examination of a number of computers belonging to Avoca Capital Holdings Ltd, his employer. Before the trial and in order to test those allegations and counter-allegations, the court granted an application that computer experts on behalf of Mr Mulcahy should have access to a number of the company's PCs. Clarke J held that such access was necessary to ensure fair procedures in the litigation, and imposed conditions to ensure that Mr Mulcahy's experts would not have access to any information that was confidential to the company.

The IT experts proposed to use advanced software and state-of-the-art systems in undertaking their forensic investigation of the relevant computers, and sought the court's confirmation that their proprietary methods could be kept confidential in the trial. Significantly, Clarke J said "no". He ruled that the forensic investigators were not entitled to protection of their proprietary methods, because a person who offered himself or herself as an expert for the purposes of litigation must be taken to be willing to have the expert's processes examined by the court. This would be especially so in the event of any conflict arising between the evidence of that expert and the evidence of another expert. However, the judge also held that a court should not make any order that would unnecessarily expose the skills of an expert, suggesting that a judge should open an expert's proprietary methods to examination by the opposing party in the litigation, only if to do so would be necessary to determine an issue in the trial.