Unless otherwise agreed by the parties, if, without showing sufficient cause:

(1) The claimant fails to communicate its statement of claim in accordance with RCW 7.05.340(1), the arbitral tribunal shall terminate the proceedings;

(2) The respondent fails to communicate its statements of defense in accordance with RCW 7.05.340(1), the arbitral tribunal shall continue the proceedings without treating such failure in itself as an admission of the claimant's allegations; and

(3) Any party fails to appear at a hearing or to produce documentary evidence, the arbitral tribunal may continue the proceedings and make the award on the evidence before it.