There may be situations where an employee was treated differently than others based on a ground protected by human rights legislation (such as age, sex, race, religion, or disability), but it does not constitute a breach of human rights legislation. In other words, some discrimination might be permissible when a particular discriminatory standard is a necessary requirement of the job, or when that occupational requirement is reasonable and justifiable. This is called a bona fide occupational requirement.
For example, it is may be a bona fide occupational requirement to require that truck drivers not be legally blind, even though this is a disability (a protected ground) under human rights legislation.
We can advise both employers and employees on what are reasonable and justifiable occupational requirements versus what standards/requirements are likely to breach human rights legislation.