16. (1) The Executive may, in writing, appoint a person to act as Commissioner—
(a) during a vacancy in the office of Commissioner, whether or not an appointment has previously been made to that office; or
(b) during any period, or during all periods, when the Commissioner is, or is expected to be, absent from duty or from Australia or is, for any reason, unable to perform the duties of the office;
but a person appointed to act during a vacancy shall not continue to act for more than 12 months.
(2) A conciliator is not eligible to be appointed under subsection (1).
(3) Anything done by or in relation to a person purporting to act in the office of Commissioner is not invalid merely because—
(a) the occasion for the appointment had not arisen;
(b) there was a defect or irregularity in connection with the appointment;
(c) the appointment had ceased to have effect; or
(d) the occasion to act had not arisen or had ceased.