(a) Order of proceeding; burden of proof. Except as may be determined otherwise by the hearing examiner, counsel supporting the complaint shall proceed first at the hearing. The Assistant Solicitor of Labor in charge of trial litigation, supporting the complaint, shall have the burden of proof. The burden of proof shall be satisfied by a preponderance of the evidence.

(b) Evidence—(1) In general. The testimony of witnesses shall be upon oath or affirmation administered by the hearing examiner and shall be subject to such cross-examination as may be required for a full and true disclosure of the facts. The hearing examiner shall exclude evidence which is immaterial, irrelevant, or unduly repetitious.

(2) Objections. If a party objects to the admission or rejection of any evidence or to the limitation of the scope of any examination or cross-examination or the failure to limit such scope, he shall state briefly the grounds for such objection. Rulings on all objections shall appear in the record. Only objections made before the hearing examiner may be relied upon subsequently in the proceeding.

(3) Exceptions. Formal exception to an adverse ruling is not required.

(c) Official notice. Official notice may be taken of any material fact not appearing in evidence in the record, which is among the traditional matters of judicial notice and also concerning which the Department by reason of its functions is presumed to be expert: Provided, That the parties shall be given adequate notice, at the hearing or by reference in the hearing examiner's decision of the matters so noticed, and shall be given adequate opportunity to show the contrary.

(d) Oral argument before the hearing examiner. Oral argument before the hearing examiner may be allowed. However, such argument may be limited by the hearing examiner to any extent that he finds necessary for the expeditious disposition of the proceeding.

(e) Transcript. Hearings shall be stenographically reported. Copies of the transcript may be obtained by the parties upon written application filed with the reporter, and upon the payment of fees at the rate provided in the agreement between the Assistant Secretary and the reporter.