Bradford Plumer weighs the evidence:
The company has a long record of safety violationsin 2005, an aging BP plant in Texas exploded, killing 15 people, and an after-action report blamed "organizational and safety deficiencies at all levels of BP." Then came a large leak that poured 267,000 gallons of oil into Prudhoe Bay, Alaska in 2006, thanks to poorly maintained pipes. And just this year, federal inspectors have found 62 safety violations at BP's Ohio refinery. Yet BP never underwent the same cultural shift that ExxonMobil underwent.
(Image: An American flag lays in a slick of oil that washed ashore from the Deepwater Horizon oil spill in the Gulf of Mexico on July 4, 2010 in Gulf Shores, Alabama. By Joe Raedle/Getty Images)