We’ve known already for quite some time that there is hardly evidence for a correlation between expertise and great teaching. This article on Inc.com shows that expertise can also have a possible bad consequence:

Using applications for medical research grants, Kevin Boudreau and his colleagues found that evaluators gave their lowest ratings to the submissions with the greatest degree of novelty. Interestingly, if an evaluator was an expert in the area, even lower ratings were given. When new ideas are introduced, people tend to regard these critically. Experts in the area, however, are even more negative.