In the event of the incapacity of the Chairman or of any member of a Committee by reason of illness or absence, or any other cause, the Commission may in the manner prescribed in subsection (2) of this section, appoint some other person qualified for appointment to that office to act in the place of the Chairman or member. Every person so appointed shall, while the incapacity continues, be deemed for all purposes to be the Chairman or member of the Committee, as the case may require.

No appointment of a deputy and no acts done by him as such, and no acts done by the Committee while any deputy is acting as such, shall in any proceedings be questioned on the ground that the occasion for his appointment had not arisen or had ceased.”