1. In contested cases each party shall be entitled to present oral arguments or written briefs at or after the hearing which shall be heard or read by each official of the agency who renders or joins in rendering the final decision.

2. In contested cases, each official of an agency who renders or joins in rendering a final decision shall, prior to such final decision, either hear all the evidence, read the full record including all the evidence, or personally consider the portions of the record cited or referred to in the arguments or briefs. The parties to a contested case may by written stipulation or by oral stipulation in the record at a hearing waive compliance with the provisions of this section.