BP choices over the course of the project-
"BP....cut short a procedure involving drilling fluid that is designed to detect gas in the well and remove it before it becomes a problem, according to documents belonging to bP and the drilling rig's owner and operator, Transocean Ltd."
"BP also skipped a quality test of the cement around the pipe- another buffer against gas- despite what BP now says were signs of problems with the cement job and despite a warning from the cement contractor Haliburton Co."
"once gas was rising, the design and procedures BP had chosen for the well likely gave the perilouss gas an easier path up and out, say well control experts...... workers, pushing to finish the job, removed a critical safeguard, the heavy drilling fluid..... BP has admitted a "fundamental mistake" in concluding it was safe to proceed with mud removal............
"Finally, a BP manager overseeing final well tests apparently had scant experience in deep water-drilling. He told investigators he was on the rig to "learn about deep water........"

Wall Street Journal, http://online.wsj.com
Ben Casselman and Russell Gold, reporters, "BP Decisions Set Stage for Disaster."