Canada’s Federal Court of Appeal Comments on Standard of Review for Claim Construction

On September 6, 2016, Canada’s Federal Court of Appeal (FCA) issued its decision dismissing the appeal of Nova Chemicals Corporation from Justice O’Keefe’s decision finding Dow Chemical Company’s Canadian Patent No. 2,160,705 to be valid and infringed (Nova Chemicals Corporation v The Dow Chemical Company, 2016 FCA 216, affirming 2014 FC 844). 

With respect to the standard of review for claim construction, the FCA emphasized that a trial judge was entitled to deference with respect to appreciation of the evidence, “particularly the expert evidence that affects the construction of a patent”.  The FCA held that, although the construction of the patent was to be reviewed on the standard of correctness, the trial judge was entitled to “some leeway” as trial judges are “often in a much better position than appellate judges to understand the intricacies of the art underlying the invention disclosed in a patent”.

The FCA found that all of the arguments raised by Nova Chemicals amounted to mere disagreements with the trial judge’s factual findings and assessment of the expert evidence.  Therefore, the FCA dismissed the appeal.