I did glance at the study but decided not to read it too much. But just because any one person doesn't fit a general trend doesn't violate a general patter. Clearly it's possible to be either tidy and not racist, or untidy and racist. Rightly or wrongly, what the study says is that there is a link between the two such that you are more likely to be concerned about "social tidiness" if you are also obsessive about tidiness elsewhere. More likely isn't certain, and I don't think it comments much on what drives the link, but there you go.