Rosenberg v. Macdonald Sager Manis LLP, 2026 ONCA 627 (CanLII)

Procedure — Appeals and leave — Costs — Courts of Justice Act, s. 133(b) — Whether leave to appeal is required for an appeal only as to costs — Appellant did not seek leave — Mullin v. Lagace applied — Appeal dismissed at end of oral submissions — Costs on appeal orderedProcedure — Leave to appeal costs — Appellate review — Whether stringent test for leave to appeal a costs award is met — No basis to conclude motion judge erred in principle or was plainly wrong — Motion judge’s reasons on variation of costs upheld — Appeal dismissedProcedure — Costs assessment and variation — Lost-opportunity costs — Whether assessment officer treated appellant’s time as if she was the lawyer — Whether lack of particulars of work foregone warranted modest compensation — Motion judge identified errors in principle and substituted more modest compensation rather than returning for inquiry — Appeal dismissedProcedure — Costs consequences — Costs of appeal — Appellant ordered to pay costs on the appeal — Inclusive of all applicable taxes and disbursements — Appeal dismissed with costs ordered against appellant — Costs ordered payable to respondent