She is there specifically to provide mental health care for the students. Which is what he was. What you are claiming is that it's unethical for her to do her job.
Yes. Because she was also a professor at the same university.
The whole set-up was unethical.
As a professor, she is in a position of influence and authority over grad students, esp. since they were both working in related fields. The psychotherapist must maintain a professional detachment and relationship of trust with her patient. Treatment requires exploration of some deeply personal and sensitive issues. As a co-worker, she was just too close personally to treat JH as a patient. His supervisors were her colleagues. And, as a member of the faculty, she may have certain conflicts of interest; for example, concerns over the school's image.
When these cases arise, the psychotherapist has an obligation to refer the patient to another therapist.