(1) Unless required for the disposition of ex parte matters specifically authorized by statute, a hearing officer shall not communicate off the record with any party to the hearing or any other person who has a direct or indirect interest in the outcome of the hearing, concerning any substantive issue, while the proceeding is pending.
(2) The prohibition stated in subsection (1) shall not apply to:
(a) Communication with other agency staff, if the communication is not an ex parte communication received by staff; and (b) Communication among members of a collegial body or panel which by law is serving as a hearing officer.
(3) If an ex parte communication occurs, the hearing officer shall note the occurrence for the record, and he shall place in the record a copy of the communication, if it was written, or a memorandum of the substance of the communication, if it was oral.