NEW : Texas board members in heated debate over whether man wrongfully executed . Jury acquitted Michael Todd Willingham after finding he set fire that killed his daughters . Legal advocate questions the objectivity of the Texas board 's chairman . Panel 's chairman calls criticism ` ` personal attacks '' and says , ` ` We 're being used ''
NEW : Texas board members in heated exchange over whether man wrongfully executed . Jury convicted Cameron Todd Willingham after finding he set fire that killed three daughters . Legal advocate questions the objectivity of the Texas board 's chairman . Panel 's chairman calls criticism `` personal attacks '' and says , `` We 're being used ''