U.S.-based Anadarko Petroleum, which owns a 25 percent stake in BP’s ruptured well in the Gulf, has been publicly criticizing its British partner for “reckless decisions and actions,” even though Anadarko itself approved well designs that many have called risky, according to the Financial Times.

In a statement last month, Anadarko said “this tragedy was preventable and the direct result of BP's reckless decisions and actions,” arguing that “BP operated unsafely and failed to monitor and react to several critical warning signs.”

The company’s criticisms of its partner, however, focus on operating decisions, and not on the well design choices that saved BP time and money — decisions that U.S. lawmakers have criticized as shortcuts. Those decisions included the use of a cheaper, “long string” well design and fewer centering devices than recommended -- both of which would have increased the risk of gas flow problems, which triggered the initial rig explosion. Anadarko had approved those designs.

Here’s what BP told the Financial Times:

BP, in a statement to the FT, explained that it gave or made available to its co-owners documents that showed the well design, changes to the well design, and identified major well control events encountered during drilling operations and that personnel from the co-owners engaged in periodic communications with BP personnel about well design and other issues related to the well.

Anadarko didn’t deny it. In fact, a company spokesman defended the well design:

John Christiansen, Anadarko's spokesman, said: "What we knew was that the design, the long string and the use of centralisers all met industry standards if executed correctly.

"The problems were caused by BP's execution of each of these."

At stake? Hundreds of millions in liability.

According to Anadarko, BP should have to foot the tab for cleanup and damages, because according to the companies’ joint operating agreement, costs incurred by gross negligence or willful misconduct on the part of BP are an exception to their liability-sharing agreement.

BP fired back, stating that it “strongly disagrees with these allegations,” and that “other parties besides BP may be responsible for costs and liabilities arising from the oil spill, and we expect those parties to live up to their obligations.” (A third company, Mitsui & Co. of Japan, has a 10 percent stake in the well.)

BP has already billed Anadarko for more than $272 million, according to an invoice obtained by Talking Points Memo.

If it sharing the costs of the disaster, Anadarko may end up being the hardest-hit partner, as Bloomberg has pointed out: By revenue, BP is 29 times the size of Anadarko, and Mitsui is five times the size.

BP has promised to pay all legitimate claims, and said the feuding between well owners will not affect that process. According to a Miami Herald piece today, it seems that process isn’t going so  smoothly either.