A BP team leader who supervised managers on the oil rig that exploded in the Gulf of Mexico in 2010 testified Monday that he was frustrated by last-minute changes to the drilling project, but didn’t have any safety concerns before the deadly blast.

John Guide was BP’s wells team leader for the Deepwater Horizon project and supervised two rig managers who have been indicted on manslaughter charges in the deaths of 11 workers. He was the first witness to testify during the eighth week of a federal trial seeking to assign responsibility for the disaster.

The explosion that killed the rig workers triggered the nation’s worst offshore oil spill. Barring a settlement, U.S. District Judge Carl Barbier, who is hearing testimony without a jury, could decide how much more money BP and its contractors owe for their roles in the catastrophe.

In an email three days before the April 20, 2010, blowout of BP’s Macondo well, Guide complained about last-minute changes and warned his boss, David Sims, that the operation wouldn’t succeed if it continued “in this manner.” Guide sent the email after learning about a change in the plan for cementing BP’s Macondo well.

“David, over the past four days there has been so many last minute changes to the operation that the (BP rig managers) have finally come to their wits end. The quote is ‘flying by the seat of our pants,'” Guide wrote.

Plaintiffs’ attorneys have cited that email as evidence that BP sacrificed safety and cut corners in a rush to complete a project that was behind schedule and millions of dollars over budget.

Guide, however, testified that the concerns he expressed in his April 17 email had nothing to do with safety.

“Were you in any way suggesting that the operations were being conducted in an unsafe manner and, therefore, could not succeed?” BP attorney Hariklia Karis asked Guide.

“No. That’s not what I meant,” he said.

Guide said he sent the email after learning that BP planned to add 30 barrels of “spacer” during the Macondo well’s cement job. A spacer is a liquid used to separate other liquids from each other.

“I didn’t know about this,” he recalled. “I was surprised.”

Robert Kaluza and Donald Vidrine, BP’s well site leaders on the rig at the time of the explosion, have pleaded not guilty to manslaughter charges and await a separate trial. An indictment last year accuses Kaluza and Vidrine of botching a key safety test and disregarding abnormally high pressure readings that were glaring signs of trouble before the blowout.

Guide said he spoke to Vidrine on the morning of April 17 and discussed the last-minute changes to the drilling plans.

“Mr. Vidrine was frustrated,” he recalled. “He made the comment that it just seemed like trying to put all this stuff together made him feel like he was flying by the seat of his pants.”

Guide said he also discussed his concerns with Brian Morel, a BP engineer on the project, before sending the email to Sims.

“Everybody wants to do the right thing, but, this huge level of paranoia from engineering leadership is driving chaos,” Guide wrote in the email. “Brian has called me numerous times trying to make sense of all the insanity.”

Guide closed out the email by asking about his authority on the project.

“With the separation of engineering and operations I do not know what I can and can’t do,” he wrote.

Guide testified Monday that he didn’t really have any questions about his authority and merely wrote that out of frustration.

BP has already pleaded guilty to manslaughter and other criminal charges and agreed to pay $4 billion in criminal penalties, but the company faces billions more in civil claims by the federal government and Gulf states. The ultimate price tag for BP will be much higher if the plaintiffs’ lawyers persuade Barbier that BP acted with gross negligence before the blowout.

Barbier also must consider how much fault to assign to rig owner Transocean Ltd. and Halliburton, BP’s cement contractor on the project.