The part you are missing here, is where you have insulated yourself financially and legally; and they don't have the means to. Maybe they are an undocumented i

The part you are missing here, is where you have insulated yourself financially and legally; and they don't have the means to. Maybe they are an undocumented immigrant, but happy to help others. Maybe they think they will be sued by someone with money if they take any money for the job (and create a larger mechanical issue).