At any time before or during a hearing, an agency attorney may withdraw a complaint or a respondent may withdraw a request for a hearing without the consent of the ALJ. If an agency attorney withdraws the complaint or a party withdraws the request for a hearing and the answer, the ALJ must dismiss the proceedings under this subpart with prejudice, unless the withdrawing party shows good cause for dismissal without prejudice, except that a party may withdraw a request for hearing without prejudice at any time before a complaint has been filed.