yeah, however these types of jobs have existed for a long time. That is what Nate Silver of 538 did before doing what he does now. He might still do it too, don't know though. So, I assume, they have contracts and other methods of mitigating that conflict. I also assume that clients/employers do what they can to know if someone like him is trying to fuck them over. There are probably some pretty nasty consequences for getting caught too. I doubt they can ever get rid of all risk but, if the person is good, I imagine the risk benefit analysis falls into the favor of using people like him. You will find these types of entities scouting university math departments, especially statistics majors.