Trial Judges Entitled To Some “Leeway” On Construction

On September 6, 2016, the Court of Appeal dismissed Nova Chemicals Corporations appeal from a judgment finding its SURPASS product infringes Canadian Patent No. 2,160,705 directed generally to polyethylene film products, such as plastic garbage bags and food wrapping. The 705 Patent was previously held valid and infringed Justice O’Keefe (see here). On appeal, Nova contested all of Justice O’Keefe’s findings regarding claims construction, validity and infringement.

With respect to claims construction the Court of Appeal, following Whirlpool, held that claims construction is a question of law and therefore reviewable on the correctness standard. The Court of Appeal did, however, continue its recent trend (see our previous post here) of noting the challenges associated with applying the correctness standard to an exercise that relies heavily on the trial judge’s evaluation of expert evidence. While recognizing that the correctness standard applies the Court of Appeal stated that trial judges are nevertheless entitled to some “leeway”:

On the other hand, the construction of the patent is to be reviewed on the basis of correctness. As the Supreme Court has stated in Whirlpool Corp. v. Camco Inc., 2000 SCC 67 at para. 61, [2000] 2 S.C.R. 1067, “claims construction is a matter of law”. That being said, I share the concerns of my colleague Justice Stratas that it will often be difficult, if not unrealistic and artificial, to distinguish between those aspects of claim construction that flow from the trial judge’s assessment of expert evidence from the words of the claim themselves (see Cobalt Pharmaceuticals Company v. Bayer Inc., 2015 FCA 116 at paras. 16-24, [2015] F.C.J. No. 555). After all, the construction of a patent is heavily dependent on the evidence given by persons skilled in the art, and that evidence will bear heavily on the judge’s findings. For that reason, I accept (as I must) that the construction of a patent is a question of law to be reviewed on a standard of correctness, but trial judges are nevertheless entitled to some leeway as they are often in a much better position than appellate judges to understand the intricacies of the art underlying the invention disclosed in a patent.

In applying this standard,  the Court of Appeal affirmed Justice O’Keefe’s construction of various terms including that the word “comprising” means “including, but not limited to”.

When addressing Nova’s argument regarding the alleged promise of the patent, the Court of Appeal noted that Nova’s position on the promise was somewhat ambiguous and that “such variations in the formulation of the impugned promise detract from the requirement that the promise be specific and clear”.

Regardless of what formulation of the promise Nova relied upon, each one depended on a promise of synergistically enhanced properties. The Court of Appeal pointed out that these words are used on only two occasions at page 1 of the patent, are nowhere defined in the patent and are absent from the claims:

However one looks at the ‘705 Patent, two crucial facts stand out: there is not a single statement of utility in Dow’s claims, as acknowledged by Nova, and there is only one reference elsewhere in the specification to support an argument of enhanced utility. I agree with Dow that the Court should be wary of using a stray phrase on page 1 of the patent to define the promise of the patent.

The Court of Appeal held that Justice O’Keefe could find that an explicit promise was not made and that the patent satisfied the test of a “mere scintilla” of utility. With respect to the remainder of Nova’s arguments, the Court of Appeal noted that Nova failed to demonstrate any error of law and their arguments amounted to nothing more than disagreements with Justice O’Keefe’s findings:

All of the arguments raised by the appellant amount to no more than mere disagreements with the Judge’s factual findings and assessment of the expert evidence. The Judge did not err in law, and was entitled to prefer the evidence of some experts over that of others; indeed, this is precisely the task he was called upon to fulfill, and the appellant has not established that he made any palpable and overriding error in doing so.

Nova’s appeal was dismissed in its entirety. A copy of the Court of Appeal’s Reasons for Judgment may be found here.