I had an interesting conversation with a mate about this today.
This mate of mine flew into a country NSW aerodrome about 10 years ago on a longish cross country trip, after ringing ahead re avgas and being told it was available. He arrived to find that the bowser had gone U/S a day before he rang, and was awaiting parts.
Turned out the bloke who he spoke to on the phone only drove the Jet-A1 truck, and had nothing to do with the supply of avgas; as this bloke hadn't heard anything about the busted bowser from the other bloke who looked after the avgas, he'd simply assumed that there were no issues.