Most of the reports criticizing the poor quality of the initial estimates of the BP oil disaster have focused on the oil company’s faults. But a new report goes after the Obama Administration and their underestimation of the extent of the spill. And it comes from the president’s own handpicked commission.

The Obama administration repeatedly underestimated how much oil was spilling into the Gulf of Mexico from the stricken BP well, contributing to public fear about the accident and a loss of faith in the government’s ability to handle it, according to a sharply critical staff report from the presidential commission appointed to study the disaster.

The report, one of four made public on Wednesday, is sharply critical of senior administration officials for making public a series of inaccurate estimates of the amount of oil spewing from BP’s Macondo well and how much of it remained in the Gulf of Mexico after the well was capped.

We know that the estimates started at 1,000 barrels a day, eventually rising to 60,000 a day once more sophisticated methods were used. “By initially underestimating the amount of oil flow and then, at the end of the summer, appearing to underestimate the amount of oil remaining in the gulf,” the report concluded, “the federal government created the impression that it was either not fully competent to handle the spill or not fully candid with the American people about the scope of the problem.”

The Oil Spill Commission’s Twitter feed actually approvingly tweeted out stories about this report, so they want it to be well-known that the government screwed up.

Some of the other working papers that the Oil Spill Commission released today are even more interesting. This one (PDF) looks at the amount of the oil, but also the “fate of the oil,” and whether the government “created a misleading impression that the “fate of the oil” was clear, and that a large majority of the oil was ‘gone.’” The report released that created this misimpression did not reveal its methodology, the OSC says, nor was it designed to explain the “fate of the oil” in a rigorous manner. More on this from Andrew Restuccia.

Other reports out today concern the decision making on aspects of the spill, the challenges of oil spill response in the Arctic, and the use of undersea dispersants during the BP disaster. This report reveals that cleanup crews used 1.84 million gallons of dispersants. It doesn’t come to many conclusions about that use, but it raises a number of very interesting issues, including potential future regulatory actions.

I’d say the OSC wants to portray themselves as an independent watchdog, with nobody getting a free pass.