(a) A purchaser from a corporation of its own shares is not liable to the corporation or its creditors with respect to the shares except to pay the consideration for which the shares were authorized to be issued pursuant to section six hundred twenty-one of this article or specified in the subscription agreement entered pursuant to section six hundred twenty of this article.
(b) Unless otherwise provided in the articles of incorporation, a shareholder of a corporation is not personally liable for the acts or debts of the corporation except that he or she may become personally liable by reason of his or her own acts or conduct.