I think that is a load of rubbish, only because simple economics says that that capping the well ASAP will cost BP less/be more lucrative due to the huge number of claims piling up against them. We are talking the most litigious country in the world with the largest claims awarded in the world.
I see no reason why BP would not want to salvage as much of the salvageable crude oil though. There was a link posted here earlier about the clean-up activity after a spill in the Persian gulf. I understand much of that crude was salvaged by empty supper-tankers. I assume the refining process can remove the salt water from the crude oil quite easily.