My conspiracy comment had to do with the SWAT questions...alot of people have questioned the timing (pure coincidence) and the 'SWAT' teams (good old fashioned heavy hand of government putting their boot on the necks of drilling companies)...nothing more.
A first hand account on 60 minutes described an accidental damaging of a seal in the BOP...and yet Transocean kept drilling.
And, he also described that BP ordered Transocean to cement the well in a risky way (essentially not letting the cement hydrate fully before evacuating the drill fluid between redundant plugs)
There was also mention that the BOP was known to have a bad battery in one of two redundant systems.
So it sounds like good old fashioned human error. It does not seem as if one particular part had a catastrophic failure. Instead, Transocean and BP decided to 'drive on' with damaged or unserviceable parts, and short cutted processes.