These rules are what make the "pay only for verified work" promise possible. Both sides accept them at sign-up.
Each day we open the repo, read the diff since the last check, run the app where possible, and compare what works against the original pitch and the coder's declared milestones. We then set a verified percentage and the cumulative price. Both sides see the note. Disagreements go to support inside the project page and are settled by us.