In 2015, the Ontario Court of Appeal confirmed in Moore v Getahun that it is appropriate and essential for counsel to consult and collaborate with expert witnesses in preparing expert reports. However, this practice is not without limits considering an expert’s duty to provide a fair, objective and non-partisan opinion. In this third article in a series on expert evidence, the jurisprudence on where counsel should draw the line in providing input to an expert witness is surveyed.

The Ontario Court of Appeal discussed this issue in Bruell Contracting Limited v. J. & P. Leveque Bros. Haulage Limited. This 2015 action arose out of a road surfacing contract between the Ontario Ministry of Transportation (“MTO”) and a contractor, J. & P. Leveque Bros. Haulage Limited (“Leveque”). Leveque’s first treatment of the road was unsatisfactory and the MTO ordered the treatment redone but refused to pay Leveque for the additional work. One of the issues on appeal was the trial judge’s rejection of the MTO expert witness on the basis that counsel improperly instructed and manipulated his opinion.

The Court of Appeal disagreed with the trial judge, finding nothing untoward about counsel’s communications with the expert. In response to the concern about counsel informing the expert about traffic volume information, the Court of Appeal said, “Counsel does not instruct the experts as to what conclusions they should draw from the information. Counsel leaves it to them to decide whether to include it in the report, but notes that it could be an issue at trial”. As for counsel’s recommendation to delete a quote in the report made by an MTO employee because she was not an expert on the subject, the Court of Appeal regarded this as “an exercise of judgement by counsel regarding the reliability of the report, not a deliberate suppression of information”. Lastly, the Court of Appeal looked favourably upon counsel instructing the expert not to communicate with a subsidiary whose parent company was party to the litigation, reasoning that counsel was “aware of his ethical obligations and was attempting to abide by them”.

In 2016 in Uponor AB v Heatlink Group INC, Justice Manson of the Federal Court also discussed the issue of consultation and collaboration between counsel and expert witnesses. This action concerned the infringement and validity of a patent, and the defendant retained experts to opine on the use of the invention before it had been patented. Justice Manson recognized the principle discussed in Moore v Getahun that consultation and collaboration between counsel and an expert is a necessary component of litigation. However, the judge found that counsel overstepped in this regard and reduced the weight of the expert opinions accordingly. The issue was that the literature relied on by the experts was almost exclusively chosen by counsel, which in this context, compromised the integrity of the opinions. As the judge stated, “experts are expected to conduct their own prior art [sic] searches, and not simply rely on documents provided by counsel”.

In a less common scenario that involved an expert’s interactions and communications with his own lawyer, Justice Perell decided a refusals motion in Wright v. Detour Gold Corporation. In this securities class action, the expert retained by the defendants retained his own law firm to assist in preparing his opinion. The law firm conducted research and drafted an affidavit at the expert’s direction. On cross-examination of the expert, the plaintiffs sought production of draft affidavits and all communications between the expert and his lawyers, arguing that the expert had clearly been unduly influenced. Justice Perrell upheld the refusals stating that, “It is hardly surprising that an expert has assistance in preparing and drafting his or her opinion… [the expert] swore under oath and under cross-examination that he was the author of the substance of the opinion. There is no reason to doubt his word just because his own lawyer’s helped him in forming his words.” Indeed, the judge commented that the practice in this case was to be encouraged, rather than discouraged, as it enhanced the expert witness’s independence and impartiality and insulated him from the potential pressure of the party’s lawyer to be a more partisan witness.

Overall, while the level of input that is acceptable from counsel to an expert is largely context-dependent, cases subsequent to Moore provide some general guidance on this point. It seems to be proper for counsel to inform the expert of relevant information that the expert may not otherwise obtain, but counsel for the party who retained the expert should be careful not to conduct the majority of the expert’s research. Furthermore, it appears acceptable for counsel to provide substantive edits to a draft report, or even draft an affidavit to be sworn by the expert, and to give instruction about who the expert cannot contact, so long as counsel’s actions are aimed at bolstering the reliability of the report without compromising its independence.