I assume the individual has a claim with WCB. WCB accepts claims for mental health/psychological injuries in the case of harassment.

When somebody has a WCB claim, generally they cannot take legal action against their employer for their work injury. There are portions of the Workers' Compensation Act that deal with this. This is why WCB coverage also benefits employers .... it stops them from being sued if somebody is hurt on the job, but the worker is compensated for their injury.

It seems from the article that they are challenging some of the legislation (not just the workers' comp act) that normally would not allow for legal action in this kind of situation.