S.C. Code § 55-5-160
Except as otherwise provided in this chapter, in order to facilitate the making of investigations by the division, in the interest of the public safety and the promotion of aeronautics, the public interest requires and it is therefore provided that the reports of investigations or hearings, or any part thereof or any testimony given thereat, shall not be admitted in evidence or used for any purpose in any suit, action or proceeding growing out of any matter referred to in said investigation, hearing or report thereof, except in case of criminal or other proceedings instituted by or in behalf of the division under the provisions of this chapter; nor shall any employee of the division be required to testify to any facts ascertained in, or information gained by reason of, his official capacity and, further, no employee of the division shall be required to testify as an expert witness in any suit, action or proceeding involving any aircraft.
S.C. Code § 55-5-160