Mo. Rev. Stat. § 334.128
Any person who reports or provides information to the board, or any person who assists the board, including, but not limited to, physicians' health programs and individuals working, consulting with or staffing such physicians' health programs approved by the board for impaired physicians, applicants or licensees who are the subject of an investigation, physicians serving on competency panels, medical record custodians, consultants, attorneys, board members, agents, employees or expert witnesses, in the course of any investigation, hearing or other proceeding conducted by or before the board pursuant to the provisions of this chapter and who does so in good faith and without malice shall not be subject to an action for civil damages as a result thereof, and no cause of action shall arise against him or her as a result of his or her conduct pursuant to this section. The attorney general shall defend such persons in any such action or proceeding.
§ 334.128, RSMo