The crux of the argument seems to hang on this statement (linked to from the article):

  If we can't cap that hole that oil is going to
  destroy the oceans of the world. It only takes
  one quart of motor oil to make 250,000 gallons
  of ocean water toxic to wildlife. Are you starting
  to get the magnitude of this?

Would be great to have some secondary sources/opinions on this. Is that true? And if so, how much damage could this leak cause?