Rarotonga, 2010

Simon's Megalomaniacal Legal Resources


ADMINISTRATIVE LAW | SPPA / Fairness (Administrative)

home / about / Democracy, Law and Duty / testimonials / Conditions of Use

Civil and Administrative
Litigation Opinions
for Self-Reppers


Patents - Evidence

. dTechs EPM Ltd. v. British Columbia Hydro and Power Authority

In dTechs EPM Ltd. v. British Columbia Hydro and Power Authority (Fed CA, 2023) the Federal Court of Appeal considered the particular role of expert evidence in patent litigation:
[32] In patent cases, it is not unusual for expert reports to be prepared in close collaboration with counsel in an effort to present the substantive opinion of the expert in a manner and format that is helpful to the Court in light of the complexity of the issues raised. Here, I am not only referring to the technical issues, per se, but to the complex questions that need to be answered because of the particular role of experts in patent cases. It is very rare indeed that technical experts will know how to present a claim analysis or be familiar with the legal principles applicable to matters such as claim construction, anticipation or obviousness.

[33] As a practical matter, it is known that extensive notes are taken during meetings with experts to help prepare the draft reports, and that counsel are actively involved in putting these reports together. This does not inevitably mean that those drafts do not reflect the substantive and objective opinion expressed by the expert during those meetings. The preparation of those reports is often a long, tedious, and iterative process. It is obviously a difficult task for counsel to ensure that the independence and credibility of the expert is not diminished by this well-known and necessary practice in this particular field. I must reiterate that I am only dealing with patent cases here.

[34] I agree with the appellant that there are, however, limits to the involvement of counsel. The Court must ultimately be presented with the substantive and objective opinion of the expert. This is why experts are very clearly put on notice of their duty towards the Federal Court when they agree to abide by the Code of Conduct for Expert Witnesses. I know of no cases where an expert report was excluded in a patent case on the sole ground that the first draft of said report was penned by counsel after meetings with the expert to discuss their opinions in detail. While counsel may make mistakes and overstep the bounds of what is permissible involvement, this will normally be revealed on cross-examination at trial, and will be considered by trial courts in assessing the evidence (Medimmune Ltd. v. Novartis Pharmaceuticals UK Ltd., [2011] EWHC 1668 (Pat.) (Medimmune).

[35] Thus, litigators involved in patent cases ought to be alert and alive to their duty to verify whether those limits were infringed by obtaining, through cross-examination, the information necessary for the Court to assess if the opinion presented by the expert is truly their own objective opinion.

[36] As noted in Moore v. Getahun, 2015 ONCA 55 at paragraph 61 (Moore) (citing Medimmune at para. 111), partisan expert evidence is almost always exposed as such in cross-examination. In patent cases, often, a simple review of the structure and wording of the report or the answers given in cross-examination will give an air of reality to the suggestion that counsel improperly influenced an expert witness.

[37] The interest of justice and its proper administration would not be served if one could simply wait to review an expert’s invoices after the trial to argue that a new trial should take place on the basis of information contained therein. Naturally, there may be exceptional cases but these should be rare.


[52] As mentioned earlier, for at least 20 years, this Court has acknowledged that it is not unusual, in patent cases, for counsel to prepare the first draft of an expert’s affidavits or statements (Janssen Pharmaceutica Inc. v. Apotex Inc. (C.A.), 2001 FCA 247 at para. 53). Contrary to the appellant’s contention at the hearing, expert affidavits are no different than the reports before us. In fact, the Rules use the terms "“affidavit”" or "“statement”" to refer to such evidence, even though they are commonly referred to as reports.

[53] Even the Ontario Court of Appeal recognized the need, in some highly technical areas such as patent law, for a high level of instruction by the lawyers to expert witnesses, which may require a high degree of consultation involving an iterative process through a number of drafts (Moore at para. 55).


The author has waived all copyright and related or neighboring rights to this Isthatlegal.ca webpage.

Last modified: 30-05-23
By: admin