Well put. I've been using him in my classes on persuasive/argumentative essays to show how the open-endedness of science (where argument belongs) can be compromised when people engage those who put their claims out as non-negotiables (persuasion). For Dawkins, his non-negotiable is the scientific method (fair enough?), but he betrays that at a variety of points when he comes out with his attacks on religion (failing, e.g., to acknowledge the variety of ways the term itself can be understood, and not being flexible himself in how he uses it - failing, in other words, to actually communicate with the people he confronts). Messy!