On May 9 2012 the Ontario Court of Appeal released its decision in Alfano v Piersanti, upholding the trial judge's decision following a three-day voir dire that the evidence of the defendant's proposed expert was inadmissible on the basis that the expert was neither objective nor independent. The case is a useful reminder that where an expert witness appears to be an advocate for his or her client and to lack the essential qualities of objectivity and independence, it can be argued that the expert's evidence should not be admitted, and that in determining whether to admit the evidence, the court may consider communications between the expert and the party. An expert's lack of independence does not go solely to the weight of his or her evidence. The case confirms that while a lawyer may act as a hired gun, at least in Canada, an expert may not.


Alfano v Piersanti concerned a dispute over Osler Paving and Construction Limited, a company that was incorporated by the Alfano family with the assistance of lawyer Christian Piersanti. Piersanti was given a 10% interest in the company and the Alfano family held the other 90%. When the relationship between Piersanti and the Alfano family began to deteriorate, Piersanti locked the Alfano family out of the business; when the Alfano family commenced an action seeking, among other things, a declaration that the Alfano family owned 87% of Osler, Piersanti assigned Osler into bankruptcy without consulting the Alfanos.

Following the trial, the trial judge held that Piersanti had improperly assigned Osler into bankruptcy as part of a fraudulent scheme to deprive the Alfano family of its interest in Osler, and awarded damages to the Alfano family of C$20 million and punitive damages of C$250,000. The defendants appealed this decision, as well as the judge's decision, following a three-day voir dire, to exclude the evidence of the defendants' proposed expert witness on accounting issues and damages.

While the appellants raised a number of issues on appeal in respect of liability and damages, the most significant issue on appeal, as the Ontario Court of Appeal itself pointed out, was whether the judge had erred in refusing to permit the appellants' expert to testify on the grounds that he lacked independence.

Voir dire ruling

At trial, the defendants proposed to call an accountant as an expert to give evidence with respect to the forensic accounting and the Alfanos' damages claim. Counsel for the plaintiffs objected to the admissibility of the expert's two reports on the grounds that the expert and his associates had assumed the role of advocates and were not acting independently. The issue of the admissibility of the evidence was addressed during a three-day voir dire, at which the expert was examined as a witness.

Following the voir dire, the judge held that the proposed expert's evidence was inadmissible. She reasoned that an expert must be objective and cannot "buy into" the theory of one side of the case to the exclusion of the other. The fundamental principle with respect to the admission of expert evidence is that such evidence must assist the court. If it becomes apparent that an expert has adhered to and promoted his or her client's theory of the case, he or she becomes less reliable.

Based on her review of emails between Piersanti and the accountant, the judge determined that:

  • the accountant had based his analysis on Piersanti's theory;
  • he was committed to advancing his client's theory of the case; and
  • accordingly, he had assumed the role of advocate for his client.

His reports were tainted by a lack of impartiality and were therefore inadmissible.


On appeal, the appellants argued that the trial judge had erred in refusing to admit the expert's evidence on the basis that he lacked independence and objectivity. They argued that any lack of independence should go to the weight of the evidence, not its admissibility, and that in any event the expert's reports were impartial and objective. The appellants also argued that the trial judge had erred in considering the email exchanges in arriving at her conclusion that the expert's evidence lacked independence.

According to the appellants, the trial judge should have confined her analysis to the expert's reports and his evidence concerning the content of the reports.

The Ontario Court of Appeal reviewed the criteria for the admissibility of expert evidence set out in R v Mohan, as follows:

  • relevance;
  • necessity in assisting the trier of fact;
  • the absence of any exclusionary rule; and
  • proper qualification.

Writing for the court of appeal, Associate Chief Justice O'Connor focused on the second requirement: necessity in assisting the trier of fact. He confirmed that the court must determine whether a proposed expert is capable of assisting the trier of fact by providing information likely to be beyond the trier's knowledge and experience. The court must also examine an expert's independence or objectivity – a biased expert is unlikely to be able to assist the court.

Experts must remain objective and should not become advocates of their clients' positions. The court of appeal also relied on Justice Farley's decision in Bank of Montreal v Citak (another case in which expert evidence was excluded) for the proposition that experts must be neutral and objective. To the extent that an expert is not neutral and objective, he or she is not properly qualified to give expert opinions.

It is obvious that experts are likely to support their clients' positions at trial. However, as the court of appeal held, expert reports "should not be influenced as to form or content by exigencies of the litigation or by pressure from the client". Rather, the expert's opinion should result from its independent analysis. The court of appeal then addressed the remedies available where an expert is found to be biased. In most cases, bias or lack of independence on the part of an expert is addressed by giving the report little weight, rather than by excluding the expert's report. However, the court retains the discretion to exclude the evidence of a proposed expert witness where that evidence is "so tainted by bias or partiality as to render it of minimal or no assistance".

In considering whether to admit expert evidence in the face of concerns about independence, a trial judge may conduct a voir dire and have regard to any relevant matters that bear on the expert's independence, including the expert's report and the nature of the expert's retainer, as well as materials and communications that form part of the process by which the expert formed the opinions that will be the basis of the proposed testimony.

The court of appeal did not interfere with the trial judge's decision to exclude the expert's evidence on the basis that he lacked independence, as this decision was supported by the evidence and was based on the appropriate legal principles. The expert's reports were repetitious and argumentative and went beyond the areas in which the expert was qualified to give an opinion. The expert had also addressed factual and legal issues that were to be considered by the trial judge. In addition, the emails between the expert and Piersanti indicated that the expert was attempting to craft his report to achieve the plaintiff's objectives, and in order to bolster Piersanti's position. This was a sufficient basis for the trial judge to conclude that the expert evidence should not be admitted.


The Ontario Court of Appeal's decision suggests that in instructing experts, care should be taken not to communicate in a way that could lead a judge to conclude that the expert has been coached or encouraged to modify or tailor his or her report to bolster the client's position in the litigation. Counsel should maintain control of all communications with the expert, as direct unguarded communications between the client and the expert may cross the line and taint the independence of the expert. The court of appeal specifically held that in a voir dire, a judge may look at the nature of the expert's retainer and the communications and materials that form part of the process by which the expert formed his or her opinions, including all communications with the party for which the expert is testifying. In Alfano v Piersanti it was the direct emails between the litigants and their expert that appear to have persuaded both the trial and appeal courts to exclude the expert's evidence.

Conversely, where an opposing expert appears to be an advocate or otherwise to lack independence, it is open to counsel to move to have that expert's evidence excluded – rather than to argue only that such evidence should be accorded minimal weight. Where an expert is argumentative, goes beyond the area in which he or she has expertise or has arrived at evidentiary or legal conclusions that are for the trial judge to determine, the court may exclude that expert's evidence entirely on the basis of lack of objectivity and independence. Counsel may also explore the extent to which the expert relies on a particular law firm or client for future work, and the extent to which the retainer includes a contingency fee that would motivate the expert to advocate for the client (as was the case in Citak).

Finally, it is open to opposing counsel to request production of the written communications between counsel or client and the expert, including the retainer, in support of the request to exclude the expert's evidence. Such communications, or the retainer itself, may provide the basis on which an expert's evidence is excluded, as was the case here. Such communications are not protected by litigation privilege once the expert is tendered as a witness.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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