I am not convinced that the blowout was just human error. I agree that human error certainly contributed. However, I think that the blowout may have occurred even if all procedures were followed. I think a stronger BOP was required in addition to eliminating the well failures.
Might I suggest ... Sabotage?
The BOP is the last line of defence before you lose control of the well. In the article, Mr. Barr lays out the several occasions that actions of the personnel involved could have controlled the well, even without closing the BOP, had the appropriate actions been taken.
Maybe, maybe not. Really hard to make that case though, considering some moronic, cowardly or dastardly human was apparently calling the shots to ignore & bypass one warning sign and potential solution after another. That's enough for me.
Question is - why? Does BP employ incompetents? Why were obvious warning signs ignored and orders given to move full steam ahead? Once humans are involved and identified as the primary culprits, the sky's the limit.
Imagining the scenario that must have been taking place as one warning sign after another was ignored reminded me of the chapter in Atlas Shrugged where the morons and cowards working for Taggart Transcontinental bowed to political and administrative pressure, refused to take personal responsibility to do the right thing, and sent the train into the tunnel - ultimately resulting in huge loss of life & property. Sounds similar to this situation.
What makes you think that when that and other similar BOPs worked up until that string of errors with documented consequences?