At no time after the petition is served and filed shall any member of the board or the hearing officer, who are deciding the petition, consult any person on any issue of fact except upon notice and opportunity for all parties to participate, save to the extent required for the disposition of ex parte matters authorized by law. Any ex parte memorandum or other written communication addressed to a board member or the hearing officer, by or on behalf of any party, shall be regarded as argument made in the proceeding and shall be served on all other parties.
Haw. Code R. § 6-23-47