The White House oil spill commission said on Monday it found no evidence to support accusations that the largest offshore oil spill in U.S. history happened because BP Plc and its partners cut corners to save money.
"To date we have not seen a single instance where a human being made a conscious decision to favor dollars over safety," the commission's Chief Counsel Fred Bartlit said at a meeting exploring the causes of the Gulf of Mexico spill.
Bartlit said the panel agreed with about 90 percent of the findings of BP's internal investigation of the accident released this summer. BP's report assigned much of the blame for the accident to its drilling partners.
Some lawmakers and critics have accused BP and other companies involved in drilling the well of sacrificing safety for monetary savings in the run-up to the rig explosion that killed 11 workers and unleashed millions of barrels of oil into the Gulf over the summer.
But Bartlit said the commission's preliminary investigation found no evidence of this, and that it instead found that a series of factors ultimately contributed to the explosion.
Still, Bartlit emphasized that not everything done on the rig was safe. The investigating team found that BP took unnecessary risks as it tried to temporarily abandon the Macondo well.
Workers for BP and Transocean, the owner of the Deepwater Horizon rig, also misread a critical negative pressure test of cement used in an attempt to plug the well. The panel's investigators said workers may have misinterpreted the test because neither of the companies nor the government had standard procedures for handling negative pressure tests.
When the rig's crew finally discovered the influx of hydrocarbons from the well, there were several options that could have delayed or prevented the explosion, the commission's investigative team said.
Bartlit released a stinging report last month that said Halliburton Co used flawed cement in BP's doomed Macondo well.
The report did not absolve BP of blame, but its sharp criticism of Halliburton's cementing job sent that company's stock down as much at 16 percent.
On Monday, Halliburton's shares were up 4.3 pct, while Transocean's shares were up 5.5 pct. BP was off 1.37 percent.
As he presented the commission's preliminary findings, Bartlit stressed that the probe was not focused on legal liability or assigning blame.
"We're not looking for scapegoats," commission co-chair Bob Graham, a former U.S. Senator from Florida, said at the start of the meeting.
Representatives from BP and Halliburton, as well as Transocean Ltd, were scheduled to present their perspectives on the events that led to the spill.
BP has accused Halliburton of using an unstable cement design and said Transocean failed to test the automatic shut-off function on the blowout preventer before it was used on the rig.
Transocean has denied those charges and said BP's well design was a key factor in the accident. Halliburton has also defended its cement work on the well, and blamed other actions for causing the explosion.
It will be difficult to work out the discrepancies between the companies without the legal power to compel testimony from company representatives under oath, Bartlit said.
"I can't subpoena people. I wish I could," Bartlit said. "I think it's damn important."
Although a measure providing the panel with subpoena power passed the House of Representatives earlier this year, the measure was held up by partisan gridlock in the Senate.
President Barack Obama created the seven-member commission in the aftermath of the drilling accident. Its ultimate charge is to develop proposals to prevent and respond to major spills in the future.
The panel's two-day session this week will also explore offshore drilling regulation, with a presentation from the head of the Interior Department's drilling agency Michael Bromwich on Tuesday.
Marvin Odum, president of Shell Oil Company, and Rex Tillerson, chief executive of Exxon Mobil, will also appear before the panel on Tuesday to discuss industry safety.