In the end it really does not matter. The Oil is from the earth, and in time the earth will absorb and distribute it. In the timeline of the planet, and the small amount of sea and bird life that may be lost, its really meaningless. We live in an age that agonizes over every dirty duck stuck in the oil muck. Its sad, and svcks, but in the end Oil is still needed for now and will continue to be required. There are risks associated with the production and transport of it. In time accidents will happen. Its the cost of our function. In time perhaps that will change, but not anytime soon.
BP is a company that is responsible for taking all possible measure to ensure that the transport and production is as safe as possible. That being said, crap happens, you deal with it and the earth moves on. Make BP the bad man if it makes you feel more justified for your consumption of the product they sell. But it will not change the fact that this is a part of human life in this century. As long as we learn form our failings and attempt to correct shortcomings, then we are being as responsible as can be expected. Any expectation over that is purely academic that serves as flue for debate over the human condition. Nothing more.