Experts and bias

Does becoming a noted expert mean you stick to your high horse? Is changing your mind become a quality experts should be immune to? Why was flip flopping seen as such a foible in the 2004 and 2008 US presidential campaigns?

I do remember Richard Dawkins had once recounted one of his professor's humble acceptance of having been wrong about one of his theories in favor of being witness to a new discovery.

Pride may be a reason for not accepting any of your opponent's reasoning, but it makes you appear stubborn, to put it crudely.

Or maybe sticking to your position is just your inability to be a clever argumentarian such as Socrates. I think credit should be given when it is deserved and accepting when you are wrong shows you to be the better man. That is, you may maintain your pride by being gracious at the fellow with whom yor are speaking for enriching you with something you did not know before.