I was interning at Exxon when the Deepwater Horizon oil spill happened. The mood really changed as soon as BP threw a binding agent into the oil spill, coagulating the oil and sinking it below the surface (a recommendation that Exxon's upstream research arm was proud to have recommended).

I also lived near the Alabama gulf coast and had friends that lived on the coast. Those globs of oil washed up on shore for a long time, years if I'm not mistaken. I don't know if there was any good research done to see if the environmental impact was better or worse but it would be interesting to see how it would have compared.

The PR value was huge though. Its amazing how quickly the popular sentiment can chill out when the problem is no longer easily visible.