Although the Secretary may promote traditional health care practices, consistent with the Service standards for the provision of health care, health promotion, and disease prevention under this chapter, the United States is not liable for any provision of traditional health care practices pursuant to this chapter that results in damage, injury, or death to a patient. Nothing in this subsection shall be construed to alter any liability or other obligation that the United States may otherwise have under the Indian Self-Determination and Education Assistance Act (25 U.S.C. 450 et seq.) 1