Maybe I'm being naïve and idealistic, but I would think an open source project would have a much easier time of navigating this than a private individual. Open source projects are built off of donations of both money and time. As for what is being returned, the project itself existing helps enable many businesses leading to many people becoming rich. As for expenditures, large open source projects are open with how they spend their money, so where the money ends up going is easy to see as well. There is far less ability for something nefarious to be going on for why a person is being paid.