Federal Court of Appeal Reaffirms: The Right Expert is Critical


Last week, the Federal Court of Appeal published its decision in Bombardier Recreational Products v. Arctic Cat, 2018 FCA 172. The decision is notable for reaffirming the well-settled patent law doctrines of claim construction and insufficiency of description.

In the decision under appeal, the Federal Court dismissed Bombardier’s claim that Arctic Cat had infringed four patents. The first patent claimed snowmobiles having an “engine cradle”, which Arctic Cat was held not to infringe. The Federal Court construed “engine cradle” to mean a “walled engine cradle”, which Arctic Cat’s snowmobiles did not have. The remaining three patents related to the rider’s seating position on a snowmobile. The Federal Court held that these patents would have been infringed had they not been invalid for insufficient description.

Bombardier appealed all of these holdings. The Federal Court of Appeal allowed the appeal in-part, reversed the Federal Court’s construction of “engine cradle”, and remitted validity of the first patent and remedies to the Federal Court. As part of its analysis, the Federal Court of Appeal re-emphasized several longstanding canons of claim construction, including the importance of selecting a properly qualified expert.

The balance of Bombardier’s appeal was dismissed.

Claim Construction

On appeal, the sole claim construction issue was the meaning of the claim term engine cradle, which appeared in every claim of the first patent.[1]

In the course of its reasons, the appeal court echoed the now well-settled standard of review: patent construction is a matter of law technically subject to correctness – but – holdings based on expert evidence about how the skilled person would understand the patent are reviewable for palpable and overriding error.[2]

Relying on expert evidence, the Federal Court below held a walled engine cradle (as opposed to Arctic Cat’s open-sided engine cradle) was required to fall within the claims. The Federal Court of Appeal held that the Federal Court erred in a number of ways.

First, the Federal Court had preferred the evidence of the wrong expert. Only two experts had opined on the meaning of engine cradle, one expert each for Bombardier and Arctic Cat. Arctic Cat’s expert, whose evidence the Federal Court accepted, was held by the Federal Court of Appeal not to be qualified in the specific field of the skilled person, snowmobile design.[3] His expertise – mechanical engineering and vehicle design – was too general for him to know the common general knowledge at the relevant time, some of which was experiential and not recorded in the literature. Being provided the prior art by counsel was no substitute for experience in the field:

This is always a risk when a party relies on a wider definition of the POSITA that fits the qualification of its expert…

…common general knowledge includes that which is “passed from person to person ‘on the job’…‘[j]ust as one might learn to cook at mother’s elbow, it is not all in the recipe book’”. [Arctic Cat’s expert] may well have been provided with prior art by [Arctic Cat’s] counsel, but this could not in any way qualify him to speak to the common general knowledge of the POSITA in 2000 including the meaning of a term of the art used in the claims.[4]

The appeal court held that Arctic Cat’s expert’s evidence should have been given no weight, and the Federal Court had reversibly erred. Having otherwise accepted Bombardier’s expert, who was qualified in the relevant field, the Federal Court should not have accepted Arctic Cat’s expert.[5] The appeal court treated the Federal Court’s reliance on the unqualified expert as an error of law.

Second, the Federal Court erred by limiting its construction of engine cradle to the preferred embodiments and drawings which depicted walled engine cradles,[6] despite Bombardier’s expert’s evidence and the common general knowledge to the contrary,[7] and despite the patent itself stating that the invention was not limited to its preferred embodiments.[8]

Finally, the Federal Court erred by construing the meaning of engine cradle with extrinsic evidence, including other patents and patent applications, and the inventors’ own subjective beliefs about what had been invented.[9]

Insufficiency of Description

Bombardier’s appeal from the Federal Court’s insufficiency holding was dismissed; though, the Federal Court of Appeal held that the lower court had erred in conflating the two prongs of sufficient description: disclosure, which has a strict test, and enablement, which allows some non-inventive trial-and-error to implement the invention.[10] Ultimately, however, the lower court’s error was immaterial.[11]

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[1] At para. 19.

[2] At para. 16, citing Apotex Inc. v. AstraZeneca Canada Inc., 2017 FCA 9 at paras. 29-30. See also Cobalt Pharmaceuticals Company v. Bayer Inc., 2015 FCA 116 at paras. 12-15 (“Bayer”) and cases cited therein.

[3] At para. 25.

[4]  At paras. 30-33, citations omitted.

[5] See paras. 36, 38.

[6] At paras. 43-47, 54, 57.

[7] At paras. 41-44, 45-46, 50.

[8] At paras. 43, 55.

[9] At paras. 22-23, 51. See also Lovell Manufacturing Co. v. Beatty Brothers Ltd., 1962 CarswellNat 22 at para 48 (Ex. Ct.); Johnson Controls Inc. v. Varta Batteries Ltd., 1984 CarswellNat 581 at para. 69 (Fed. C.A.); Nekoosa Packaging Corp. v. AMCA International Ltd., 1994 CarswellNat 2980 at para. 23; Pallman Maschinenfabrik GmbH Co. KG v. CAE Machinery Ltd., 1995 CarswellNat 149 at para. 53 (Fed. T.D.); and Shire Canada Inc. v. Apotex Inc., 2016 FC 382 at para. 122.

[10] At paras. 78, 80, 85. See also Bayer, supra, note 2 at para. 68 and cases cited therein.

[11] At paras. 79-84, 86-93.



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