On Friday a spokesman for Transocean said he couldn't confirm or deny whether the conversation took place. He was unable to make Harrell available for an interview.

During hearings held late last month by the Coast Guard and the Minerals Management Service, Harrell denied any conflicts with his BP or Transocean bosses. He said that he did not feel pressured to rush the completion of the well, even though the rig had fallen behind schedule.

Yet Buzbee's claims add weight to other statements that contradict Harrell's version of events. Testifying before the Coast Guard and MMS panel last month, Douglas Brown, the chief mechanic on the Deepwater Horizon, said that on the morning of the day that the rig exploded Harrell had a "skirmish" over drilling procedures during a meeting with BP's "company man," well site leader Robert Kaluza. "I remember the company man saying this is how it's going to be," Brown told the panel. As Harrell was leaving the meeting, according to Brown, "He pretty much grumbled, 'I guess that's what we have those pincers for,'" referring to the blowout preventer on the sea floor that is supposed to be the last resort to prevent a leak in the event of an emergency. The blowout preventer failed following the explosion on the rig, causing the massive spill. (Transocean's chief electronics technician, Mike Williams, also recalled the argument but named a different BP "company man," BP's top official on the rig, Donald Vidrine).

In a statement to the Wall Street Journal, Transocean appeared to back the claims that Harrell had feuded with BP: "The testimony certainly seems to suggest that [Harrell] disagreed with the operator's instructions, but what those were and why he disagreed are matters that will ultimately be determined during the course of investigations."

Other rig workers have also claimed that they were pressured by BP and their supervisors to cut corners. Transocean roustabout Truitt Crawford told the Coast Guard that he overheard senior management saying that BP was "taking shortcuts" by replacing drilling mud in the well with saltwater, which would have provided less weight to contain the well's surging pressure. Transocean's Williams told 60 Minutes that a supervisor had dismissed evidence that the well's blowout preventer had been damaged. And workers with Halliburton, the well's cementing contractor, had complained that BP's use of cement "was against our best practices" and told the oil company that it would likely have "a SEVERE gas flow problem" unless the well's casings were centered more carefully.

Buzbee told Mother Jones that the sailor's version of Harrell's phone conversation following the explosion was corroborated by a statement from a second crew member who says he also overheard the call. Both statements were taken in-person by Buzbee's investigator and safety consultant, who has interviewed some 60 people involved in the disaster, and signed by the witnesses, he said. Buzbee declined to make the full statements available to Mother Jones because, he said, "it is work product, meaning that it is something that I do not have to produce or disclose in litigation but that can be used at the right time in the litigation." He added that he intends to take a deposition from the crew members at a later time.