18. (1) The Minister may, in writing, appoint a person to act as the Coordinator—
(a) during a vacancy in the office of the Coordinator, whether or not an appointment has previously been made to the office; or
(b) during any period, or during all periods, when the Coordinator is for any reason unable to perform the functions of the office.
(2) A person appointed to act as the Coordinator during a vacancy in the office of Coordinator shall not so act continuously for more than 12 months.
(3) Anything done by or in relation to a person purporting to act pursuant to an appointment under subsection (1) is not invalid on the ground that—
(a) the appointment was ineffective or had ceased to have effect; or
(b) the occasion to act had not arisen or had ceased.