Heck, in a rare instance, like PPL who like to talk on phones and stuff while refueling, bad things can happen. It is actually a state law to turn off vehicles while refueling, but some do, some don't, except under certain circumstances (Texas Transportation Code - TRANSP § 647.011. Fuel Restrictions). That not bother me as much as the "clowns" smoking while refueling, especially when it gets really hot, and U can just see the "fumes" in the air. We even blew up an immersion heater one day being in a hurry to get lit and not taking proper precautions. Good way to burn yer eyebrows off, lol.
Saw a KC-135 (Strato tanker) being refueled on the parking ramp one day. The FMS person either failed to follow procedure or something came loose, ie., static line. Fuel tanks in belly caught fire and that plane burned to the concrete, with only outer parts of both wings and 2 engines surviving. Talk about a bonfire.