This question sometimes involves a judgment call. The physiotherapist should have learned of the sexual abuse while practising the profession.
A person who operates a facility (employer) should have reasonable grounds to believe that a regulated health care provider who practices at the facility has sexually abused a patient.
Rumour or innuendo does not constitute reasonable grounds however concrete information from a credible source such as a patient, the parent of a patient, a guardian or custodian, or other third party could all be sources of credible information.
A physiotherapist may have reasonable grounds to suspect that a patient has been sexually abused even if he or she has not spoken to the patient.