I agree with you. Unfortunately the phrase is used because we in the helping professions are required to have a back-up. If we are in private practice and have no one who can be on-call, we use that phrase. It's definitely a problem in the mental health field because Black people experiencing a mental health crisis are the ones most likely to be shot by police. It does seem odd that a doctor's office would use it. Did they also give you a number for a person on-call?