From Houston (BN): A legal wrinkle has surfaced in the late stages of the US government’s suit against BP for the 2010 MACONDO (31/20) spill.

Testimony in the Clean Water Act-Oil Pollution Act of 1990 case raised the uncertainty that parent BP plc would help BP Exploration & Production, the unit the government is suing, to pay up. It may be a distinction that doesn’t represent a real difference, but BP E&P is one of only two named defendants left in the government case. Partner Anadarko is the other, fighting a potential $1bn penalty.

Although legally BP E&P has been targeted in the civil pollution case since the case began - government lawyer’s said in opening statements they wouldn’t try to ‘pierce the corporate veil’ separating BP E&P and BP - it seems a subtle shift in BP’s position.

BP’s 2013 annual report said it paid $4.5bn in criminal pollution fines and set aside $42bn to cover individual damage claims and other losses in the spill. The question now is, is there a distinction being made between paying those damaged and the government? Will BP E&P take the fall after Bob Dudley walked Gulf Coast beaches promising to clean up the mess and has touted its ‘commitment to America.’

BP in London and the Department of Justice did not respond to queries about whether that is one possible outcome.

In reporting a $969mn loss for the fourth quarter, BP said its total cumulative pre-tax charge for the spill now equals $43.5bn. An additional charge of $477mn was taken in Q4 reflecting increased provision for litigation costs, additional business economic loss claims and the ongoing costs of the Gulf Coast Restoration Organization.