As a story with a different outcome, my mom parked in a BART parking lot at around 2:30pm one day. This particular lot became free at 3pm, so she had to pay for that half hour, but couldn't figure out where to pay. She went to the station agent to ask. The agent replied, "Eh, it's really hot out today. There's no way I'm going out there to check people's parking. Don't worry about paying." She did not get a ticket.