For a reason specified in §B of this regulation, an administrative unit or the Department may revoke, in whole or in part, the delegation of authority to the Office of Administrative Hearings to hear a contested case at any time before the earlier of: The issuance of a ruling on a substantive issue; or The taking of oral testimony from the first witness. The administrative unit or the Department may revoke the delegation of authority if, in the opinion of the administrative unit or the Department: A contested case involves: Unanticipated, novel, or unique legal or factual issues; or Significant social, fiscal, legal, or policy issues; or It is in the best interests of the parties to the case. The administrative unit or the Department shall provide written notice of a revocation of hearing authority to all parties and the Office of Administrative Hearings. The notice shall: State the reason for the revocation of the delegation of authority; and Specify if the revocation is in whole or in part. If only a partial revocation of the delegation of authority is made, the administrative unit or the Department shall identify in the notice the portions of the contested case for which delegation of authority has been revoked. A final decision issued by the administrative unit shall reflect the fact of full or partial revocation of the delegation of authority, and a copy of the revocation notice shall be included as part of the record.