Witnesses at a hearing shall testify under oath or affirmation.
The examiner may examine the witnesses and shall allow the parties or their representatives to do so.
If the examiner conducts the examination of a witness, he or she may allow the parties to suggest matters as to which they desire the witness to be questioned, and the examiner shall do so if such matters are relevant and material to any issue pending for decision before him or her.
D.C. Mun. Regs. tit. 18, r. 18-1031