When Can an Employer Dismiss an Employee Who is on Leave?

Here is a nice clear discussion by Toronto lawyer (and fellow blogger) Stuart Rudner of an issue I that I too have been asked about before . Stuart discusses some misconceptions about whether an employer can dismiss an employee who has taken a legally recognized leave of absence, or who is off on a disability leave.
Do you think this law strikes an appropriate balance between the concerns of the employees and those of the employer?