Now here is something interesting:

http://www.telegraph.co.uk/finance/newsbysector/energy/oilandgas/7964890/Oil-spill-safety-valve-was-wrongly-plumbed-on-rig-says-

Harry Thierens, BP's vice president for drilling and completions, told a US political hearing that the blowout preventer was connected to a test pipe, rather than the correct one.

"It would mean that the pipe rams could not be closed," Mr Thierens said in evidence to a federal panel on Wednesday. "I was frankly astonished that this could have happened."

On Tuesday, one of the survivors of BP's Deepwater Horizon explosion admitted to the hearing that his bonus was in part based on how quickly repairs were carried out.

That now explains how our guys could not shut the bloody thing off on the 22nd April.