Can an employer force an employee to produce a medical certificate every time they fail to meet a certain threshold?

In the case of Bell Canada v. Unifor, Local 6007, 2019 CanLII 6150 (CA LA), the use of an attendance management policy was found to be discriminatory and contrary to the CHRA when it was applied mechanically and without discretion. It states in part as follows at paragraph 81: 81 … [I]t is inappropriate, and an unreasonable exercise of management rights to mechanically require every employee to produce medical certificates for all future absences simply because s/he has crossed a particular threshold of absenteeism, without addressing the circumstances peculiar to the employee. Indeed, demanding that any employee whose absence the employer does not suspect is not for legitimate non-culpable reasons for all future absences is unreasonable and unfair – although requiring periodic updates may be acceptable in the case of a chronic medical condition which results in intermittent, perhaps not foreseeable, absences from work…. [Emphasis in the original]