First of all, he's an outlier in the field of research. Let's be very clear.
When you do social or physical sciences, you go with the weight of the evidence. You don't go with one study here or there. It's the same as global warming. I can show you some junk science that says there's no such thing as global warming. You know that in the scientific community it is not a question. There are numerous questions to be asked, but nobody's saying there's no such thing as global warming. I would put Dr. Fisher in the same example as a global warming denier.