Prosecutors said David Rainey, in the early days of the spill, had manipulated calculations to match a far-too-low government estimate of the amount of oil spewing into the Gulf following the explosion of the Deepwater Horizon drilling rig. He was charged with lying about having done so during a 2011 interview with federal investigators. However, defence attorneys said Rainey's figures were made honestly and that he had no reason to lie.
"I agree with the verdict," said U.S. District Judge Kurt Engelhardt said as he thanked the jurors.
"We respect the jury's verdict," said Leo Tsao, a federal prosecutor speaking after the trial.
Eleven rig workers died in the Deepwater Horizon explosion, which resulted in the nation's worst offshore oil spill. A federal judge overseeing civil litigation in the case ruled this year that roughly 3.19 million barrels spilled before the damaged well was capped — a rate of more than 36,000 barrels per day. Various early estimates were much lower. Rainey's trial focused on an early National Oceanic and Atmospheric Administration estimate, days after the spill began, of about 5,000 barrels a day, and whether Rainey had "backed into" his own calculations to match that estimate.
Outside the courtroom, defence attorney Reid Weingarten reiterated to reporters what he had told the jurors — that Rainey should never have been charged. "There was overwhelming evidence that our client acted in good faith," Weingarten said, adding that Rainey had been tasked with estimating the flow of oil at a time, soon after the explosion, when there was too little information to make accurate scientific calculations. "It was a fool's errand. It was demanded by politicians and the press. And he reluctantly took up the cudgel and came up with his best response."
Rainey himself smiled but declined to talk to reporters as he walked briskly out of the courtroom to hug family members.
Rainey also faced a charge of obstructing a congressional investigation but Engelhardt dismissed that charge this week, in part because members of Congress, including Massachusetts Democratic Sen. Ed Markey, could not be subpoenaed to testify.
Rainey was one of a handful of people charged criminally in connection with the disaster.
A former BP engineer, Kurt Mix, was convicted on one of two criminal counts in 2013 after prosecutors said he deleted text messages about the oil flow following the explosion. His conviction was overturned because a jury forewoman tainted deadlocked deliberations by mentioning she had heard something outside the trial that affirmed her view of Mix's guilt. Prosecutors have asked an appellate court to reinstate the conviction rather than have them try Mix again.
Trial is pending for BP well site leaders Robert Kaluza and Donald Vidrine, who have pleaded not guilty to manslaughter charges stemming from the 11 deaths.
Anthony Badalamenti, a former manager for Halliburton Energy Services Inc., BP's cement contractor on the rig, was sentenced to one year of probation for destroying evidence in the aftermath of the spill.
Associated Press reporter Rebecca Santana contributed to this report.