At least BP quickly took responsibility for the accident unlike American Exxon

Exxon was widely criticized for its slow response to cleaning up the disaster and John Devens, the mayor of Valdez, has said his community felt betrayed by Exxon's inadequate response to the crisis (Wikipedia)

http://en.wikipedia.org/wiki/Exxon_Valdez_oil_spill 

Why BP and not the American operators?

Why Is America going after BP rather than the American owned company Transocean - the rig owner that operates the rig under the Marshalese flag of convenience. Is it because they are American or is because they don't have a "special relationship" with the Marshalese people to screw them for billions of $$$?

Who do the Americans think they are lecturing BP about oil spills?