In statements to the press, BP representatives have said that calculating the flow of oil is somehow "not relevant" or "might even detract" or "would not affect" the company's response to the disaster in the Gulf. Problem is, this directly contradicts what BP said in its own documents--drafted before the accident--about volume being "the priority issue" when responding to oil spills.

In its 582-page Oil Spill Response Plan for the Gulf of Mexico region, BP noted that in the case of an oil spill, determining its size and volume were "critical to initiating and sustaining an effective response."

"When a spill has been verified and located, the priority issue will be to estimate and report the volume and measurements of the spill as soon as possible," Page 6 of the document reads.

After the Deepwater Horizon drilling rig exploded and sank in the Gulf of Mexico on April 20, it took four days before a spill was reported.

It took five more days before the Coast Guard and BP settled on a 5,000-barrels-a-day estimate of oil flow. They stuck to that number for the better part of the next month, even while scientists estimated the rate was several times higher. And when scientists offered to help measure the spill, as we noted, BP turned those offers down. Here's what a company spokesman told The New York Times at that time:

"The answer is no to that," a BP spokesman, Tom Mueller, said on Saturday. "We're not going to take any extra efforts now to calculate flow there at this point. It's not relevant to the response effort, and it might even detract from the response effort."

Here's another comment, also to the Times:

Speaking more broadly about the company's policy on measuring the leak, a spokesman, David H. Nicholas, said in an e-mail message that "the estimated rate of flow would not affect either the direction or scale of our response, which is the largest in history."

That's not what the company said in its Oil Spill Response Plan, which was approved by regulators at the Minerals Management Service in 2008.

When asked about the company's lack of interest in obtaining more accurate measurements of the Gulf gusher, another BP spokesman, Graham MacEwen, told me, "it's kind of a case of damned if you do and damned if you don't," because the company provided estimates that turned out to be "fairly inaccurate," but the discrepancy wasn't due to a lack of transparency.

"We've been totally open as much as we can with how much oil has been spilled so far," MacEwen said.