(1) Where two or more cases pending before a Commissioner arise out of the same accident and any issue involved in common to two or more such cases, such cases may so far as the evidence bearing on such issue is concerned, be heard simultaneously.
(2) Where action is taken under sub-rule (1) the evidence bearing on the common issue or issues shall be recorded on the record of one case, and the Commissioner shall certify under his hand on the record of any such other case the extent to which the evidence so recorded applies to such other case, and the fact that the parties to such other case had the opportunity of being present, and, if they were present, of cross examining the witnesses.