An individual who has served as prosecutor in an adjudicative proceeding may not serve as hearing examiner or assist or advise a hearing examiner in the same adjudicative proceeding. A person who has participated in a determination of probable cause or other equivalent preliminary determination in an adjudicative proceeding may serve as hearing examiner or as a final decision maker, or may assist or advise a hearing examiner or final decision maker in the same adjudicative proceeding, unless a party demonstrates grounds for disqualification in accordance with Regulation .10. A person is not disqualified from serving as a hearing examiner or final decision maker at an adjudicative proceeding because of participation at a prior nonadjudicative proceeding involving the same matter.