Haw. Code R. § 11-271-108
At no time after the issuance of the complaint shall the hearing officer discuss ex parte the merits of the proceeding with any interested person outside the department, with any department staff member who performs a prosecutorial or investigative function in such proceeding or a factually related proceeding, or with any representative of such person. Any ex parte memorandum or other communication addressed to the hearing officer during the pendency of the proceeding and relating to the merits thereof, by or on behalf of any party shall be regarded as argument made in the proceeding and shall be served upon all other parties. The other parties shall be given an opportunity to reply to such memorandum or communication.
Haw. Code R. § 11-271-108