(a) Unless required for the disposition of an ex parte matter authorized by law, a member or employee of a state agency assigned to render a decision or to make findings of fact and conclusions of law in a contested case may not directly or indirectly communicate in connection with an issue of fact or law with a state agency, person, party, or a representative of those entities, except on notice and opportunity for each party to participate.
(b) A state agency member may communicate ex parte with another member of the agency unless prohibited by other law.

(c) Under § 2001.090, a member or employee of a state agency assigned to render a decision or to make findings of fact and conclusions of law in a contested case may communicate ex parte with an agency employee who has not participated in a hearing in the case for the purpose of using the special skills or knowledge of the agency and its staff in evaluating the evidence.