A former Vedder, Price shareholder falsely overbilled a firm client by $251,863, the state lawyer-discipline commission administrator’s office alleges. From at least Jan. 1, 2012, through July 31, 2013, James A. Spizzo was the partner in charge of billing related to the firm’s representation of a large, publicly owned client. The firm represented the client, who is not identified in the Attorney Registration & Disciplinary Commission complaint issued this week, in various matters including an inquiry …