(a) A private mental hospital licensed under this chapter may authorize the disposal of any medical record on or after the 10th anniversary of the date on which the patient who is the subject of the record was last treated in the hospital.
(b) If a patient was younger than 18 years of age when last treated, the hospital may authorize the disposal of records relating to the patient on or after the later of the patient's 20th birthday or the 10th anniversary of the date on which the patient was last treated.
(c) The hospital may not destroy medical records that relate to any matter that is involved in litigation if the hospital knows that the litigation has not been finally resolved.