This applies to BP but also all the oil companies because every single field which is a bit large ($1B investment) is collaboration of many companies with one operator.
Check here, it is really interesting: http://www.offshore-technology.com/projects/
We are all closing our eyes when they pay the dividends and provide cheap gas for the SUVs.
Even in the article it shows that the government in the US is not doing its job: "BP snubbed the Environmental Protection Agency's suggestion to stop using Correxit. In response, the EPA blandly called for a "study" of other dispersants". A good gov. would have simply stopped BP with crazy huge per day of use fine.
In Europe, BP cannot operate that way (at least in Germany) because when they are not following the rules or when the TÜV (independent very strong control organization) say "we are not happy" the refinery is stopped from one day to another. The full refinery stopped.
But when the government does not care or pushes for profits because it is part of it the results are ugly. In Nigeria, the delta is dead thanks to Total and Shell way worse than in the gulf of Mexico but nobody cares and the gov. there just want money now.
Sad, but as long as we depend so much on oil for energy, it will continue.
The EPA et. al. have considered Corexit to just fine, given the alternatives, for at least a couple of decades. That BP was correct to tell the EPA to sod off can be judged by how this manufactured controversy disappeared so quickly.