Saying that hospital staff killed your dad is a bit of a stretch, but you do deserve an autopsy like you asked for.Reaching out to get records from the hospital and getting a lawyer could help. You could also reach out to the medical examiners office and see if theyre even aware of this case, if they havent heard of it, or if they rejected it.
In my hospital, the surgeon has no decision making in a coroners case. A mandatory coroners case is if a patient dies within 24 hours of admission. Furthermore, if any patient dies in my hospital, the charge RN or patients RN calls 1) the coroners office. 2) organ donation. 3). The family, and 4) the funeral home or cremation. The surgeon has nothing to do with the decision of a coroners case, the coroner decides. If the coroner decides no autopsy is warranted, the family may have there own independent autopsy completed at their own expense. Your fathers surgeon signed off because your father was no longer his patient. I hope this helps, and I am truly sorry about your father.