Employee paying for your gas.

Thought I'd bring this here to Controversy corner to see your opinions on said topic. A post was made on a popular Facebook page for our city. A woman said that she was was at Co-op gas station and requested to the young man who was working pumping gas to fill her tank with said amount of money. He did, but he filled it more than she requested by accident. (No idea how much more as she wouldn't tell anyone) He than paid for her gas with his own money. The comments came rolling in and some said that was nice, others said he probably would of been fired if he had not and others said she should repay him somehow or reimburse him for the money he spent and that most likely was half his pay cheque right there. She deleted the post. What would you of done if said worker filled your tank more than requested by accident? Make them pay? Pay yourself? 🤔