Lawmakers repeatedly hammered BP executives about allegations that the company failed to adequately address concerns raised by its own pipeline workers over the past five years, in part because of an atmosphere of fear and intimidation under the supervision of Woollam. Steve Marshall, the president of BP Exploration Alaska Inc., conceded that Woollam's "abrasive nature" and "intimidation" may have silenced workers. In 2004, BP hired the Houston-based law firm Vinson & Elkins to conduct an internal investigation of alleged workplace harassment and pipeline-corrosion data falsification.