Take notice… single hose. Means liquid gasoline is going in the tank, but where are the vapors going if there is not a vapor return hose back to the truck? ALSO, the tank has an atmospheric vent pipe somewhere so as to vent vapor pressure should the tank get warmer and the gasoline Vp increases. Add to it that the density of gasoline vapor is nearly 2X the weight of air, and any vapor that is loose will be on the ground.
Lastly, the Minimum Ignition Energy (MIE) of gasoline vapor is less than 1.0 mJ, meaning the shock we get when we touch the doorknob on a dry winter day is about 15X the energy needed to ignite gasoline vapor.
Pay attention to the group of people sitting at the cafe table in the lower left of the screen. The young man lights his cigarette and throws the match to the ground, igniting the vapors from the unloading activity. But look at all the other ignition sources within the hazard zone! No way —these parking spots and cafe tables should not be allowed so close to such a hazardous task.