Can Champion use cumulative misconduct to prove just cause for dismissal?

Champion cannot use cumulative misconduct to prove just cause without having employed clear and effective warnings and the progressive discipline approach. In a unanimous decision in Lowery v. Calgary (City) (2002), 312 A.R. 393, 2002 ABCA 237, Berger J.A. stated at para. 3 that, where cumulative cause for dismissal for incompetence is alleged, the employer must prove: 1. The employee was given express and clear warnings about his performance. 2. The employee was given a reasonable opportunity to improve his performance after the warning was issued. 3. Notwithstanding the foregoing, the employee failed to improve his performance. 4. The cumulative failings “would prejudice the proper conduct of the employer's business.”