BP finally faced off in court Monday against an army of federal and state prosecutors, lawyers and even its contract partners over the Gulf of Mexico oil spill three years ago, contending that it alone should not shoulder blame for the rig explosion that killed 11 workers and soiled beaches and marshes from Louisiana to Florida. BP’s share of responsibility is not only the crux of the trial that opened Monday, but it also is at the heart of a last-minute settlement proposal offered by the Justice Department and the five affected gulf states…that are demanding that BP pay $16 billion in spill-related fines and penalties. [also refers to Transocean, Halliburton]