If a trial or hearing has been commenced and the judicial officer is unable to proceed, then, by order of the chief judge, any other judicial officer may proceed with it upon certifying familiarity with the record and determining that the proceedings in the case may be completed without prejudice to the parties. In a hearing or trial without a jury, the successor judicial officer shall at the request of a party recall any witness whose testimony is material and disputed and who is available to testify again without undue burden. The successor judicial officer may also recall any other witness.