Can the person in charge of my grievance change my punishment if my contract doesn't say what should happen?

Because you are part of a union and are going through a formal grievance process, your case will likely be heard by an arbitrator. An arbitrator is a neutral third party chosen to resolve disputes between an employer and a union [cite:ca-labour-code-sec57]. Under the Canada Labour Code, the arbitrator has specific powers regarding discipline. The law states that "Where an arbitrator or arbitration board determines that an employee has been discharged or disciplined by an employer for cause and the collective agreement does not contain a specific penalty for the infraction that is the subject of the arbitration, the arbitrator or arbitration board has power to substitute for the discharge or discipline such other penalty as to the arbitrator or arbitration board seems just and reasonable in the circumstances" [cite:ca-labour-code-sec60]. In your specific situation, since your union representative confirmed that your collective agreement does not list a specific penalty for being late a few times, the arbitrator has the legal power to step in. Even though the company decided to fire you on the spot on October 12th, the arbitrator can decide that a different punishment is more appropriate. For example, if the arbitrator believes your misunderstanding with the clock-in programme makes firing you too harsh, they can choose a penalty that they consider "just and reasonable," such as a suspension or a formal warning instead of losing your job [cite:ca-labour-code-sec60]. It is important to note that the arbitrator's power to change the penalty is specifically tied to the fact that your rulebook (the collective agreement) is silent on the exact consequence for this specific infraction [cite:ca-labour-code-sec60]. If the agreement had explicitly stated that 'three instances of lateness equals immediate termination,' the arbitrator's ability to change that would be different.