The decision maker may adopt, modify, or rewrite a presiding officer's findings of fact and proposed conclusions of law. If a decision maker, or a majority of them, has not heard the evidence, a proposed decision, including findings of fact and conclusions of law, shall be mailed to all parties. Parties adversely affected by the decision shall be afforded the opportunity, within 15 days after receipt of it, to file exceptions and present argument to the decision maker or the majority of them. The final decision shall identify any changes, modifications, or amendments to the proposed decision and the reasons for the changes, modifications, or amendments. Copies of the final decision and findings of fact and conclusions of law shall be delivered or mailed promptly to all parties or their attorneys. Instead of a decision, a contested case may be disposed of by stipulation, settlement, consent order, default, withdrawal, summary disposition, or dismissal.