14 C.F.R. § 1264.113 – Separation of functions.

(a) The investigating official, the reviewing official, and any employee or agent of the authority who takes part in investigating, preparing, or presenting a particular case may not, in such case or a factually related case—
1. (1) Participate in the hearing as the presiding officer;
2. (2) Participate or advise in the initial decision or the review of the initial decision by the authority head, except as a witness or as the authority representative in the administrative or judicial proceedings; or
3. (3) Make the collection of penalties and assessments under 31 U.S.C. 3806.
(b) The presiding officer shall not be responsible to, or subject to the supervision or direction of, the investigating official or the reviewing official.
(c) Except as provided in paragraph (a) of this section, the representative for the Government must be a member of the legal staff of the authority. Nothing in this paragraph is intended to prevent assistance to the Government representative by attorneys in the NASA organization or other governmental entities.