Tenn. Code Ann. § 65-3-116: Officers or employees testifying exempt from indictment

No officer, agent, servant, or employee of any such company, who appears and testifies before the department of transportation under this chapter or chapter 5 of this title or in any civil or criminal proceedings instituted by the department of transportation under this chapter or chapter 5 of this title, shall be liable to indictment or presentment for any violation of this chapter or chapter 5 of this title about which such person so testifies.