Tex. Bus. Orgs. Code § 21.727

The shareholders of a close corporation described by Section 21.725 are subject to any liability imposed on a director of a corporation by this chapter or other law for a managerial act of or omission made by the shareholders or any other person empowered to manage the business and affairs of the close corporation under a shareholders' agreement and relating to the business and affairs of the close corporation, if the action is required by law to be undertaken by the board of directors.