Jet fuel that is dumped at altitude evaporates.
It never reaches the ground.
It would have to be a heavier oil to make a slick. If it was in the water because the fuel tanks broke up upon impact, an oil slick could be there. They could tell by analyzing the residue.
Thanks. So much knowledge here. Actually I was commenting on lacrew’s theory.
How low would the plane have to be flying for any dumped fuel to make it to the surface instead of evaporating?