(a) General rule. The Director may review a ruling of the presiding officer prior to the certification of the record to the Director only in accordance with the procedures set forth in this section.

(b) Scope of review. The Director may exercise interlocutory review of a ruling of the presiding officer if the Director finds that:

(1) The ruling involves a controlling question of law or policy as to which substantial grounds exist for a difference of opinion;

(2) Immediate review of the ruling may materially advance the ultimate termination of the proceeding;

(3) Subsequent modification of the ruling at the conclusion of the proceeding would be an inadequate remedy; or

(4) Subsequent modification of the ruling would cause unusual delay or expense.

(c) Procedure. Any motion for interlocutory review shall be filed by a party with the presiding officer within 10 days of his or her ruling. Upon the expiration of the time for filing all responses, the presiding officer shall refer the matter to the Director for final disposition. In referring the matter to the Director, the presiding officer may indicate agreement or disagreement with the asserted grounds for interlocutory review of the ruling in question.

(d) Suspension of proceeding. Neither a request for interlocutory review nor any disposition of such a request by the Director under this section suspends or stays the proceeding unless otherwise ordered by the presiding officer or the Director.