The other is that the belief in testability being the only source of truth, itself, being untestable, is a self-weakening statement. The Maverick Philosopher does a good job here. What's interesting to me is that it was Bertrand Russell who The M.P. quotes - who is a kind of Dawkins with intelligence, wit and substance.
Personally I'll stick to my own belief, that if you're in the scientific world it's the empirical method that works. Let's put it this way - even Boko Haram, who believe that Western education is forbidden, use weapons that have been developed using Newton's laws of motion and the results of chemical developments based on Western education and the empirical method. They may be a bunch of murdering gets, but they still know that Western methods work.