(a) Except as provided by Subsection (b), in an authority in which the principal municipality has a population of less than 1.3 million or more than 1.9 million, an action of the board is not invalid because a ground for removal of a board member exists.
(b) An action that was taken when a ground for removal under § 451.510(4) existed and that would not have passed the board without the vote of the person who is the subject of the ground for removal is voidable.