|(a) The hearing officer shall not participate in ex parte communications, directly or indirectly, in any matter in connection with any substantive issue, with any interested person or party. Likewise, no person shall attempt to engage in ex parte communications with the hearing officer on behalf of any interested person or party. (b) If the hearing officer receives any such ex parte communication, the other parties shall be given an opportunity to review any such ex parte communication. (c) Nothing shall prevent the hearing officer from communicating with parties or their representatives about routine matters such as requests for continuances or opportunities to inspect the file. (d) The hearing officer may initiate communications with an impartial Agency employee who has not participated in a hearing or any determination in the case for the limited purpose of using the special skills or knowledge of the Agency and its staff in evaluating the evidence.