This seems to be obscure information. At least we have a report from @Dereknocue67 that it isn’t the drivers adding the dye in the delivery truck. Back in the original thread @dtilque tells us that the drivers do put the additives in gasoline in the delivery truck. In that case, no one would notice if the driver didn’t put the additives in. It could be a crime to do omit the dye with diesel.