First Semmelweis, then Pasteur:
http://en.wikipedia.org/wiki/Ignaz_Semmelweis#Conflict_with_...
http://en.wikipedia.org/wiki/Louis_Pasteur
Copernicus and Galileo vs a lot of other people:
http://en.wikipedia.org/wiki/Galileo_Galilei#Controversy_ove...
http://en.wikipedia.org/wiki/Nicolaus_Copernicus
Einstein and relativity:
http://en.wikipedia.org/wiki/Criticism_of_the_theory_of_rela...
I could do this for days if you'd like. Credentials are worth something of course, but credentials don't have metaphysical powers that prevent a person from being wrong once they have their credentials.
EDIT:
That's not to say I necessarily believe that these folks are correct and Dawkins is wrong. Just that the credentials don't mean as much as people think they should. It's not like getting a PhD prevents you from ever having a bias ever again. It'd be great if it was true, but it's not.