In all three cases, the policy is consistent as the three cases all dealt with a physician’s duty to warn others beyond the patient themselves- even if it seemed to violate the privacy rules normally expected in a physician-patient relationship.
All three can really be derived off an earlier case Tarasoff v. Regents of University of California, 551 P.2d 334 (Cal. 1976) which was a landmark decision of a physician’s (here a psychologist) duty to warn a person in contact with a patient of imminent or foreseeable danger. In this case, the California Supreme Court ruled that the psychologist had a duty to warn a potential victim that they were in imminent danger by a patient who had professed his desire to kill the victim. In this case, the victim was murdered and the court ruled that the psychologist was civilly liable even if the warning would have violated confidentiality.
Each of the three expand (four if you include Tarasoff) on the duty to warn by a physician. In all three of the decisions, the courts of last resort for each