The bottom line is that BP was directed by the EPA to find (identify) a alternative dispersant withing 24 hours. BP responded by claiming that only Corexit was in adequate supply and basically thumbed their noses at the directive because they knew that they could.
Corexit is on the list of approved dispersants and the EPA can only prohibit it's use if they take the steps to unapprove it. Which obviously takes an act of congress. Not that the EPA wanted to stop the use anyway. If they did, they wouldn't have come up with such a wishy-washy, mealy-mouthed directive in the first place.
The use of Corexit has been banned in Britian. But that's only because it has been proven to wipe out those pesky snails and crustaceans. Who needs em anyway?
BP doesn't want to spend the money to switch to a less harmful dispersant until they have used up the stuff that they have already stockpiled and have on hand. Their bottom line is way more important to them than the welfare of the Gulf.
I guess if I were a stockholder I would be happy.