When a ship is in a fog at night and some oil comes out of that ship in that fog at night, it is not impossible — in fact, it is often very possible — to prove that that oil came from that ship because oil has a fingerprint.
Lorsqu'un navire se trouve dans le brouillard, la nuit, et que des hydrocarbures se déversent de ce navire, il n'est pas impossible — en fait, il est souvent fort possible — de prouver que ces hydrocarbures provenaient de ce navire, car on peut les retracer.