The appellant unions appealed a Divisional Court decision that quashed an Ontario Labour Relations Board ruling.
The Board had admitted a photocopy of the 1958 Sarnia Working Agreement into evidence as a business record and ancient document, finding it created province-wide bargaining rights binding the respondent employer.
The Board also found the unions were estopped from enforcing the agreement for two years due to representations made in 2000.
The Divisional Court ruled the document inadmissible and substituted a permanent estoppel.
The Court of Appeal allowed the appeal, holding that the Divisional Court failed to show deference to the Board's evidentiary rulings and remedial discretion, restoring the Board's original decision.