It happens all the time. People find large amounts of money in inconspicuous bags at unlikely places. They pick it up and return it. Sometimes it’s millions of dollars, sometimes it’s less; but it’s always a big enough sum to make newspaper headlines, or else we wouldn’t know about it.
Why they do it and whether you and I would do it if it were us who found the money is not important right now. The important thing is that those people had a choice and made a decision. By opting to return the money, they’ve chosen to lose it. Irreversibly.
Games are rubbish at offering players that kind of genuine dilemma. Before I go on, a warning: there will be spoilers once you take the jump.