If the canvassing board decides to take corrective action with respect to errors or discrepancies described in WAC 434-262-050, the canvassing board shall prepare a written narrative of the errors or discrepancies discovered, the cause of those errors, if known, and the corrective action taken. Each member of the canvassing board must sign the written narrative and must initial the auditor's abstract of votes if it is altered or modified by the canvassing board.