-—The law has the final say.——
...and the law says what ?
At a minimum:
Art. 49.04 DEATHS REQUIRING AN INQUEST.
(a) A justice of the peace shall conduct an inquest into the death of a person who dies in the county served by the justice if:
(3) the body or a body part of a person is found, the cause or circumstances of death are unknown...
(6) the person dies without having been attended by a physician;
Art. 49.10. AUTOPSIES AND TESTS.
(e) A justice of the peace shall order an autopsy performed on a body if:
(1) the justice determines that an autopsy is necessary to determine or confirm the nature and cause of death;
(i) If a justice of the peace determines that a complete autopsy is unnecessary to confirm or determine the cause of death, the justice may order a physician to take or remove from a body a sample of body fluids, tissues, or organs in order to determine the nature and cause of death.
http://www.statutes.legis.state.tx.us/Docs/CR/htm/CR.49.htm