The only management witness who identified 35 as a critical age in ?the ability to cope with the stresses of the spare board was Tyson, and he ?did so only in response to cross-examination which was directed more to his ?personal opinion, than company policy. ###>Le seul témoin de la direction à avoir affirmé que l'âge de 35 ans est critique en ce qui a trait à la capacité de faire face au stress que comporte le travail de conducteur de relève est M. Tyson.