If, during the course of the hearing, a party first becomes aware of evidence of bias or other grounds for disqualification, the party may move for disqualification but must establish the grounds by the introduction of evidence into the record.
If the presiding officer determines that disqualification is appropriate, the presiding officer or other person shall withdraw. If the presiding officer determines that withdrawal is not required, the presiding officer shall enter an order to that effect. A party asserting disqualification may seek an interlocutory appeal under rule 13.25(17A) and seek a stay under rule 13.29(17A).
Iowa Admin. Code r. 288-13.9