Federal Court restores patent invalidity ruling after rejecting expert-independence challenge

The Federal Court has reinstated a ruling invalidating a patent claim after finding that new evidence about lawyers’ involvement in preparing an expert’s reports did not reduce the weight of his testimony.

In dTechs EPM Ltd. v. British Columbia Hydro and Power Authority, 2026 FC 1235, Justice Simon Fothergill granted BC Hydro’s motion on October 6, 2026. The decision restores the court’s earlier finding that dependent claim 4 of Canadian Patent No. 2,549,087 was invalid.

The ruling turns on evidence that the reports expressed the expert’s own opinions despite counsel’s role in writing drafts. It does not give lawyers unrestricted permission to supply an expert’s conclusions.

A narrow issue returned after appeal

In 2021, the Federal Court dismissed dTechs’ patent-infringement action against BC Hydro and Awesense Wireless Inc. and found the disputed patent claims invalid on grounds of anticipation and obviousness.

During the subsequent costs process, dTechs obtained BC Hydro’s expert’s working agreement and invoices. It relied on those documents to challenge the independence of J. Bradley Shepherd’s evidence. The invoices recorded conferences, research and reviews of drafts, but did not expressly record his writing the first drafts himself.

The Federal Court of Appeal largely dismissed dTechs’ appeal in 2023. It upheld the findings that neither defendant had infringed the asserted claims. However, it concluded that the new evidence could affect the invalidity finding for claim 4 and allowed the defendants to seek a redetermination.

The appeal court permitted the trial judge to address the effect on the expert’s evidence as a preliminary question, potentially avoiding a full reconsideration of the remaining issues. BC Hydro sought that redetermination after dTechs sent it another letter alleging infringement of claim 4.

Who supplied the opinions?

Shepherd had since died. His business partner, Curtis Falany, provided evidence about how the reports were prepared. Justice Fothergill limited that evidence to explaining the writing process and disregarded statements about Shepherd’s character or usual manner of expressing opinions.

Falany described repeated videoconferences in which counsel asked Shepherd questions and recorded his answers in a shared-screen document. The judge found that this process explained why Shepherd’s invoices did not contain entries for personally drafting the reports.

dTechs focused on an academic study about detecting electricity theft in India that had helped support the original finding against claim 4. It argued that the record did not show discussion of that study or construction of the claim before counsel sent Shepherd a draft report.

BC Hydro disputed that chronology. Falany explained that documents were renamed to record when they were received, including materials obtained through a shared Dropbox folder. The study’s filename and the surrounding records supported the conclusion that Shepherd had received it nearly a month before the draft. His invoices also recorded conferences, document review and research during that period.

After reviewing the new evidence, trial exhibits and Falany’s testimony, Justice Fothergill found that the reports reflected Shepherd’s own opinions and accurately described how they had been prepared.

Collaboration has limits

The judge relied on the appeal court’s explanation that close collaboration between counsel and experts is common in patent litigation, where technical specialists may need help presenting their analysis within the relevant legal framework. But the court must ultimately receive the expert’s substantive, objective opinion, and counsel must protect the expert’s independence and credibility.

The motion was confined to whether the additional evidence changed the weight of Shepherd’s testimony. The judge rejected dTechs’ attempt to reopen admissibility or have the evidence excluded because Shepherd was no longer available for cross-examination. He also rejected BC Hydro’s reliance on a rule requiring notice before a witness is impeached as inappropriate to this unusual situation.

The court declared that the new evidence had no impact on the weight given to Shepherd’s trial evidence and reinstated the invalidity ruling for claim 4. It did not set a costs amount: if the parties could not agree, they could make written submissions of no more than five pages within 14 days of the order.