This can't be right: A powerful corporation making a risky decision that put costs ahead of environmental safety? That's crazy talk!

About 11 hours before the Deepwater Horizon exploded, a disagreement took place between the top manager for oil giant BP PLC on the drilling rig and his counterpart for the rig's owner, Transocean Ltd., concerning the final steps in shutting down the nearly completed well, according to a worker's sworn statement.

Michael Williams, a Transocean employee who was chief electronics technician on the rig, said there was "confusion" between those high-ranking officials in an 11 a.m. meeting on the day of the rig blast, according to a sworn statement from Mr. Williams reviewed by The Wall Street Journal. Mr. Williams himself attended the meeting.

The confusion over the drilling plan in the final hours leading up to the explosion could be key to understanding the causes of the blowout and ultimately who was responsible.

What is known from drilling records and congressional testimony is that after the morning meeting, the crew began preparations to remove from the drill pipe heavy drilling "mud" that provides pressure to keep down any gas, and to replace this mud with lighter seawater.

Ultimately, the crew removed the mud before setting a final 300-foot cement plug that is typically poured as a last safeguard to prevent combustible gas from rising to the surface. Indeed, they never got the opportunity to set the plug.

[...] Typically well owner BP would have final say, since it was paying roughly $1 million a day to lease the rig and pay for services from 12 companies that had people on the rig.

What is clear is that workers soon began displacing the mud. Later that afternoon a pressure test provided ambiguous readings, a possible sign of gas seeping in, according to what Rep. Henry Waxman says a BP executive told House investigators. Eventually, in the evening, after further tests, BP made a decision to carry forth in removing more drilling mud. The rig blew about 10 p.m.