I had a friend who drove off without paying for his gas by accident. He just kind of spaced out. He likely would have appreciated a reminder over the speaker.
He didn't get too far before he realized that he hadn't paid and went back.
They had called the police and they had already arrived by the time he went back. The cop actually tried to arrest him as he tried to explain that obviously the whole reason he came back was to pay for the gas he had forgotten to before.
Fortunately it got sorted out okay, but it seemed like there was stupidity on both sides: his for spacing out, and the cop for trying to arrest him as he was trying to hand the gas slave the money.