Is the client Uber or the rider? In my corporate job I work with contractors who do full time for us for months at a time. They were paid by a placement agency, but we are the client.
> Meh... this was a big multinational so I doubt they are committing fraud.
I actually think that a big multinational is more likely to commit these kinds of frauds. In fact, a full time employee that works only for one company and who's sent by a placement agency sounds a lot like fake self-employment.