"BP and the government say the spill is fast disappearingâbut dramatic new science reveals that its worst effects may be yet to come..." http://motherjones.com/environment/2010/09/bp-ocean-cover-up
They put that dispursant on the oil that made it separate into the water and some sink to the bottom. I read that it could take decades to dispurse in the colder depths of the gulf since it needs to be near the surface to evaporate.
naturally they are going to use the best possible data to show that the mess has been expertly handled and everything is just fine. I read your link there, and what is says sounds credible. So yes, government and BP want us to put on rose colored glasses here, but that's not surprising in the least. Take everything with a grain of salt.