(a) It is a ground for removal from the board that a member:
(1) commits malfeasance of office;
(2) cannot, because of illness or disability, discharge the member's duties for a substantial part of the member's term; or
(3) is absent from more than half of the regularly scheduled board meetings that the member is eligible to attend during a calendar year, unless the absence is excused by majority vote of the board.
(b) The validity of an action of the board is not affected by the fact that it was taken when a ground for removal of a board member existed.