Unless otherwise agreed by the parties, if, without showing sufficient cause:
(a) The claimant fails to communicate his statement of claim in accordance with subsection (1) of section 50a-123 , the arbitral tribunal shall terminate the proceedings;
(b) The respondent fails to communicate his statement of defense in accordance with subsection (1) of section 50a-123 , the arbitral tribunal shall continue the proceedings without treating such failure in itself as an admission of the claimant's allegations;
(c) 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.