Standard of Review for Attributes of POSITA

AFD Petroleum Ltd v Frac Shack Inc 2018 FCA 140 Gleason JA: Webb, Laskin JJA rev’g 2017 FC 104, 2017 FC 274 Manson J

2,693,567 / Fuel Delivery System and Method

At trial in Frac Shack v AFD, Manson J held several claims of Frac Shack’s 567 patent to be valid and infringed. On appeal, the FCA has reversed in part, holding that Manson J made a palpable and overriding error in his definition of the POSITA [41]. The invention relates to a system for refueling fracking equipment while the engines are running (see here for a summary), and Manson J had initially described the POSITA as having experience designing fueling equipment for fracking systems, but had omitted this aspect of the POSITA’s from his explicit findings: [42] (contrasting FC [142] with FC [144], [154]). This was important to the subsequent analysis of obviousness, because a novel fuel delivery system might be obvious to a person with expertise in designing fracking fueling equipment, but not to a party without such expertise [43]. In light of the error, the FCA remanded obviousness and related questions to Manson J for redetermination [46]. I’m not sure much will change, as one of the Frac Shack’s experts, whose evidence was largely accepted by Manson J [FC 245], did have expertise in designing fueling equipment for fracking systems [FC 64], and the expert for AFD, whose evidence was less persuasive, did not [FC 247].

Of more general interest is the FCA’s summary of the standard of review. The FCA held that “the impugned findings in the instant case regarding the attributes of the POSITA and the extent of the POSITA’s common general knowledge are matters of fact or mixed fact and law from which a legal issue cannot be extricated” [38] and therefore subject to review only for palpable and overriding error (some citations omitted):

[39] In Mylan Pharmaceuticals ULC v. AstraZeneca Canada Inc., 2012 FCA 109, 432 N.R. 292, this Court noted that issues of construction are matters of law and therefore reviewable for correctness. However, the Court went on to note at paragraph 20 that:

[…] any assessment of the evidence (concerning the state of scientific knowledge at the relevant time, or how a reasonable POSITA would understand the patent, for example) made by the Judge in the course of reaching his conclusion on the construction of the patent is reviewable for palpable and overriding error.

[40] Similarly, in Wenzel Downhole Tools Ltd. v. National-Oilwell Canada Ltd., 2012 FCA 333, 443 N.R. 173, this Court stated at paragraph 44 that the “weight to be given to the expert evidence as to how particular words would be understood by the POSITA is a question where the trier of facts is entitled to deference.”