Or, as has happened at least once, perhaps the slightly crudded up wire got stuck in the slightly crudded up tube on the gas cap because of the tremendous blast of slipstream pressing it ever so slightly against the tube wall, preventing the float from dropping with the fuel level. I didn't see the episode and most likely never will, but is it just possible the preflight was a little rushed on an aircraft which had been out of service for a bit? That the intrepid aviator didn't dipstick the tank, didn't even open the tank to ensure the float wire was free to move?
Don't bother to ask how I learned these things whether they are or they aren't written up in any aviation safety database. Your mileage may vary.![]()