Expert Evidence: The importance of getting it right

20 November, 2015

The use of expert evidence in litigation is regulated strictly by the court once proceedings are issued: Permission is needed before expert evidence can be relied upon by any party to an action. Experts may be instructed by one party or jointly by all. Whether experts are instructed by one party or by all, their primary duty is to assist the court and that overrides any duty that the expert may have to those who are instructing or paying him or her. It is vital that this overriding duty is made very clear to an expert at the outset of any instruction. The case of Van Oord UK Limited & Another v Allseas UK Limited (2015) (a construction dispute where the value of the claim was over £10m) provides a very stark warning of the consequences of getting it wrong in an extreme case.

The facts are not important. What is, however, is that the evidence of the Claimant’s expert on quantum was wholly disregarded by the trial judge, who described it as being entirely worthless. To reinforce this view the judge proceeded to set out 12 reasons for this conclusion. These included that the expert took the Claimant’s pleaded claims at face value, only considered the Claimant’s witness statement evidence and incorporated documents in his report that he had not verified. Perhaps the most damning was when, under cross examination, the expert essentially disowned his own report. The overall impression was that the expert produced a report based on what he was told to say, rather than exercising any independent thought and wholly disregarding his overriding duty.

Where the court gives each party to litigation permission to rely upon their own expert it is natural that the expert would do his or her best to support the case of the party instructing them. While an extreme example, Van Oord clearly demonstrates there are limits on the extent to which an expert is able to do this and if the expert does clearly step over the mark the consequences can be dire.