Given the huge amount of reporting and 3rd party investigation that goes into every significant refinery, it would a rather foolish act to mislead.
What the heck is a flammable vapor that’s similar to diesel?
A refinery has lots of process units and intermediate steps prior to making a finished product. It will be a vapor because it is so hot in the process. Likely once it cools down after spending time outside the pipe, it would coalesces into a liquid.
It really isn't diesel until all the additives are in sulfur removed and meets the ASTM specification. I read that the fire started in the Crude Unit. That is one of the early steps and essentially no finished refined product comes out of that unit. In a crude distillation tower, the fluid is heated between ~625°F to ~7000°F. Most of the crude oil is turned into vapor at this point.