(1) At a meeting of the Board, a quorum is constituted by:
(a) 4 Board members; or
(b) at any time when there are only 5 Board members--3 Board members.
(2) However, if:
(a) a Board member is required by section 27J of the Commonwealth Authorities and Companies Act 1997 not to be present during the deliberations, or to take part in any decision, of the Board with respect to a particular matter; and
(b) when the member leaves the meeting concerned there is no longer a quorum present;
the remaining members at the meeting constitute a quorum for the purpose of any deliberation or decision at that meeting with respect to that matter.