A single picture from a cell phone camera may have saved the Gulf of Mexico from a few more weeks — if not months — of oil gushing from the BP well.

A new study from the presidential oil spill commission describes the behind-the-scenes, excruciating tension and mistakes behind the three-month effort to cap the busted well. New details include the story of a lone scientist working from a cell phone photo who saved the day by convincing the government that a cap it considered removing was actually working as designed.

The cap that eventually stopped the oil from flowing was almost pulled a day or so after it was installed in mid-July because pressure readings looked so low that they indicated a leak elsewhere in the system. BP wanted the cap to remain and the well to stay shut, but government science advisers were firm and near unanimous in wanting the cap removed because of fear of bigger, more catastrophic spill, the report said. One scientist took a cell phone picture and e-mailed it to a government researcher in California for advice.

Just using that cell phone photo, Paul Hsieh, a U.S. Geological Survey scientist, created a model for what was happening under the cap. He was convinced that the containment cap wouldn’t blow. He got more data, which bolstered his case. He persuaded the other scientists to wait a bit.

The government waited six hours, then a day. Nothing happened. The cap held.

Hsieh turned out to be right.

Hsieh told The Associated Press that he was “flattered that I was portrayed well,” but said others including Energy Secretary Steven Chu, who headed the scientific team, deserve the credit.

The picture Hsieh examined was “a game changer,” said University of California at Berkeley professor Bob Bea, who analyzed the report for the AP.

“It also shows how in disarray we were,” Bea said.

Monday’s draft report said some BP attempts to stop the gusher — especially the efforts dubbed Top Kill and Junk Shot — probably were doomed from the start. That’s because BP had underestimated how much oil was spilling. Both BP and the government were unprepared for capping a blowout well and cleaning up the mess it makes, the report said.

Given how unprepared they were, both BP and the government reacted quickly and impressively, the report said: “BP’s efforts to develop multiple source control options simultaneously were Herculean.”

“It was a marvelous experience in logistics,” said Bea, who wasn’t part of the spill commission.

Also, the oil industry in general and government have not spent the money they promised to improve clean-up equipment and technique for oil spills, a second commission report said.

More than anything the commission report on containment didn’t blame or praise, but pulled back the curtain on what happened during hectic times as 172 million gallons of oil gushed into the Gulf from April 20 to July 15.

Online:

The oil spill commission: http://www.oilspillcommission.gov/