dTechs EPM Ltd. v. British Columbia Hydro and Power Authority

Decided: 2026-10-06. Docket: T-227-17. Citation: 2026 FC 1235 (CanLII). Intellectual property — Patents — Validity — Dependent claim 4 — Anticipation and obviousness — Whether the Court should reinstate its prior ruling that claim 4 is invalid — Redetermination following remittal limited to impact of new evidence — Prior invalidity ruling reinstated | Evidence — Expert evidence — Weight — New evidence on drafting — Whether the new evidence admitted on appeal affects the weight attributed to the expert’s evidence at trial — Working agreement and invoices considered — Process of videoconferences and review of drafts assessed — No impact on weight declared | Evidence — Expert evidence — Cross-examination — Federal Courts Rules, Rule 279(c) — Whether expert evidence should be excluded due to u