I work have worked in mental health for over ten years in locked wards and group homes. The only time anyone has ever been taken off of a case is when the worker becomes part of a patient's delusional thought process, which can put the worker in danger or the patient has expressed an urge to harm a worker or made a threat. The inpatient ward I worked on actually required that any worker help any patient at anytime even if they were not part of our caseload. I have been called every name you can think of, had things thrown at me in fit of delusion and been harassed by clients on a daily basis. I could not, EVER, say I would not work with them again. The only time I was able to say I was uncomfortable working with someone was a patient became fixated on me sexually. I brought the issue up to my boss, she said no problem we will assign him to a male worker as he could not control his actions at the time.  Health care workers, nurses and the like, do not have the option to not work with someone because their feefees get hurt, at least where I live and work, though I think that is pretty standard. I don't now about rehabs but I know that is true for mental health. If you are a patient in a hospital for medical needs,  male nurses may be assigned to male patients but no one can say they won't care for someone without a good fucking reason. Stating health facts while sedated is not one of those reasons.