07/19/2010 11:53 pm ET Updated May 25, 2011

Hung Nguyen, Coast Guard Official, Accused Of Bullying Witnesses In Gulf Oil Spill Hearings

KENNER, La. (Associated Press) -- A Coast Guard official leading a government probe of the deadly Deepwater Horizon rig explosion was accused today by company and rig worker attorneys of trying to intimidate a witness and violating the rights of two others who have testified about the blast.

The hearing started with a testy exchange between Coast Guard Capt. Hung Nguyen, one of six panel members questioning witnesses, and lawyers for two rig workers who have been designated "parties in interest," or possible targets of the investigation.

Attorneys for Deepwater Horizon captain Curt Kuchta and Jimmy Harrell, the rig's offshore installation manager, objected that their clients weren't named parties in interest until after their testimony in May.

Pat Fanning, Harrell's attorney, said the delay deprived his client of "substantial rights."

"It is outrageous that you didn't afford him that opportunity at the very beginning of these hearings," Fanning said.

"By law, there was no presumption of guilt or innocence before the hearings proceeded," Nguyen said. "As the hearings progressed, we identified certain information that necessitated designation of Jimmy Harrell as a (party in interest)."

Kuchta's lawyer, Kyle Schonekas, said the panel "sandbagged" his client.

"It's just not fair," Schonekas said during a break.

Kuchta had testified in May about a delay in activating the rig's emergency disconnect system. The system, which didn't function after the April 20 explosion, allows the rig's "upper marine riser package" to break free from the lower part.

Harrell, who was Transocean Ltd.'s top manager aboard the rig, had testified that he never felt any pressure to accelerate the project's pace even though it was weeks behind schedule.

Nguyen also traded heated words with lawyers for Transocean, the majority owner of the rig, which was leased by BP, and with the day's first witness, Stephen Bertone, Transocean's chief engineer on the Deepwater Horizon.

Bertone testified the rig had some mechanical problems before the blowout, including malfunctioning computer equipment in a "driller's chair" and problems with a thruster that lasted for several months. But he repeatedly said he didn't know or couldn't recall many details of the rig's maintenance history.

When Nguyen cautioned Bertone that the panel would be evaluating his "knowledge, skill and performance" as part of the probe, Transocean lawyer Edward "Ned" Kohnke accused him of trying to intimidate Bertone.

"I think what you're doing now is wrong," Kohnke said. "You're trying to challenge this witness to intimidate him because he said at various times, 'I can't recall.'"

"It's my duty to make sure you are well-informed of the process of this hearing," Nguyen told Bertone.

Bertone's attorney, Steve London, interjected and said, "If he truthfully can't remember something, then I don't see why you would be sitting here threatening him."

"If this committee wants the truth, he gave truthful answers," London added.

The Coast Guard and Bureau of Ocean Energy Management, Regulation and Enforcement (formerly the Minerals Management Service) heard six days of testimony in May and scheduled five more days this week. The original witness list for this week's hearings included Donald Vidrine and Robert Kaluza, who were BP PLC's top managers aboard the rig, but neither is expected to appear.

Vidrine has been scratched from the list due to health reasons, according to a Coast Guard spokeswoman. Kaluza refused in May to testify, exercising his constitutional right not to incriminate himself. His attorney, Shaun Clarke, said Kaluza won't be testifying this week "barring something unforeseen."

The panel also heard testimony Monday from other rig workers, including drilling fluid specialist Leo Lindner, an MI Swaco employee who assisted in a procedure to displace drilling fluid with sea water in the rig's riser pipe before the explosion. Seawater would have provided less weight than mud to counter the pressure coming from the well head.

Lindner said BP decided to use an abnormally large volume of "spacer" fluid to separate the mud from the seawater as they circulated the well. Asked if that larger volume of spacer could cause any well complications, Lindner said he isn't qualified to answer an engineering question like that.