“Rav Heinemann only said that about it being permissible to see a doctor of the opposite gender (and him physically handling the patient) and it not being chiba. He did not apply it to any other situation such as handshaking.”
Thats my point from the shach, if you are really saying Yehareig V’al Yaavor a doctor shaking a female patient’s hand or performing another examination would not be any different.
I remember learning in shiur thats what rov moshe was saying.