In IP litigation, the outcome of many high-stakes cases has turned on expert testimony. It is therefore important for litigators to spend time and effort to properly identify, select and prepare expert witnesses. Effective experts may need to:
- construe complex claims through the eyes of a person skilled in the art;
- assess the state of common general knowledge;
- conduct tests to show infringement; or
- conduct surveys to assess reputation or likelihood of confusion.
This article explores the practical aspects of expert testimony with regard to selecting experts, drafting expert reports and preparing experts for cross-examination (for further details on the more theoretical aspects of expert testimony please see "Effectively using experts in IP litigation part one: theory").
The first step in the selection of expert witnesses is to identify the particular subject areas of expertise in the litigation on which evidence is required and then to search for appropriate candidates within each identified area.
Expertise is at the crux of expert witness selection, including whether the witness has the appropriate academic or professional credentials or any practical experience. The court may look to the witness's CV to help determine whether they are credible. For example, in Aventis Pharma Inc v Apotex Inc (2005 FC 1283), Justice Mactavish looked to the experts' CVs and concluded that the expert with more specialised knowledge regarding the compounds at issue was preferable to the one with more generalised knowledge, whose expertise was more diversified.
In order to avoid introducing bias, counsel may wish to solicit a potential expert's opinion without divulging who they represent or their theory of the case.
Prior litigation experience may also be beneficial, since experts who have previously testified will likely be more familiar and comfortable with the litigation process. However, counsel should carefully review any prior expert reports and testimony for potential inconsistency. Further, any decisions regarding an expert's prior testimony should be reviewed to assess credibility and how they may respond to the pressure of cross-examination. For example, the Federal Court in Varco Canada Limited v Pason Systems Corp (2013 FC 750) found previous "qualitative criticism" of an expert by three different courts to be "telling" in his failure to "maintain independence" or "put forward evidence which could materially assist the Court".
Once a list of potential expert witnesses has been generated, counsel should conduct thorough background checks and in-person interviews to:
- confirm that the witness has no conflict of interest that would prevent or interfere with their ability to act;
- assess the witness's credibility, including personal mannerisms, demeanour, control and self-discipline;
- evaluate the witness's ability to withstand cross-examination, in order to avoid witnesses that are obstructionist, confrontational or unwilling to concede any point;
- gauge the witness's initial position – since experts tend to revert to their initial position under the pressure of cross-examination; and
- confirm the witness's availability to prepare a report and testify.
Identifying an appropriate expert witness can be time consuming and challenging, but is well worth the effort.
Drafting an expert report: role of counsel
Expert reports must clearly set out all factual assumptions and explain the basis for the expert's opinion in sufficient detail to enable the court to reach its own conclusion on the disputed matters. Any experiments conducted should be fully explained and all underlying data should be included in the report. Graphics and demonstratives may assist in communicating difficult concepts. Consideration should also be given to addressing any anticipated criticism as the opportunity to reply to a responding expert may be limited. Counsel can and should work with experts in drafting the expert report to ensure that it is clear, in the proper form and addresses the relevant matters in dispute.
The Ontario Court of Appeal commented on the role of counsel in the preparation of expert reports in Moore v Getahun (2015 ONCA 55). The court rejected the trial judge's "proclamation that the practice of consultation between counsel and expert witnesses to review draft reports must end". In doing so, the court concluded that "expert witnesses need the assistance of lawyers in framing their reports in a way that is comprehensible and responsive to the pertinent legal issues in the case" and that "[c]onsultation and collaboration between counsel and expert witnesses is essential". The court also observed that in some highly technical areas, such as patent law, expert witnesses "require a high level of instruction by the lawyers", which may necessitate a "high degree of consultation" involving "an iterative process through a number of drafts".
Citing this decision, in Uponor AB v Heatlink Group Inc (2016 FC 320), the Federal Court noted that:
undoubtedly, consultation and collaboration between expert witnesses and counsel is a necessary component of litigation, particularly in highly technical cases… Nonetheless… experts are expected to conduct their own prior art searches, and not simply rely on documents provided by counsel.
This is consistent with the Supreme Court's decision in White Burgess Langille Inman v Abbott and Haliburton Co (2015 SCC 23), where the court rejected the suggestion that an expert could not give fair, objective and non-partisan evidence "simply because the expert relies on the work of other professionals in reaching [their] own opinion".
Nevertheless, it is important that the opinions provided in expert reports are those of the expert and not those of counsel. When working with experts, counsel should be careful to avoid undermining their independence (eg, Janssen Pharmaceutica Inc v Apotex Inc (2001 FCA 247)).
Prepping witnesses: practice, practice, practice
The best way to prepare expert witnesses to testify is to practise. This is particularly important for experts with little to no trial experience. However, even seasoned experts will benefit from practice.
Some useful practical tips for experts for trial include:
- remembering that their role is to inform and assist the court, not advocate or argue;
- listening carefully to the question asked;
- ensuring that they understand the question;
- being unafraid to ask for clarification;
- pausing before answering to reflect on the answer that they are about to provide and to give counsel an opportunity to object;
- answering the question asked;
- being careful of questions with absolutes (eg, 'always' or 'never');
- being careful of questions with hidden assumptions;
- always being courteous and respectful;
- speaking clearly; and
- turning to the judge when answering questions.
The most important part of preparing expert witnesses is to practise cross-examination. Role-playing is a useful technique. If possible, counsel may wish to conduct a mock cross-examination in a courtroom to familiarise experts with the environment. Videotaping a mock cross-examination may provide experts with valuable feedback. Ideally, counsel should prepare and conduct a mock cross-examination as thoroughly as opposing counsel. There should be no surprises at trial.
The recent decision in Biogen Canada Inc v Taro Pharmaceuticals Inc is a reminder of the importance of selecting and prepping witnesses. The Federal Court held that:
the parties' key witnesses' evidence was uniformly weakened on cross-examination. Given the inconsistencies of evidence, advocacy, and unreasonable positions taken by [the expert witnesses], the Court gives limited weight to their expert opinion evidence (2020 FC 621 at para 44).
Counsel who carefully select experts, provide appropriate guidance in drafting expert reports and thoroughly prepare experts for trial will significantly increase the likelihood of that expert's testimony being found credible and given full weight.
