This seems like a bug, but maybe I'm missing something. In the version i'm using, if someone has permissions to answer questions, then they are also seemingly allowed to choose their own answer the best answer. This seems strange and counterproductive. They can't vote their answer up or down, but they can choose it as the best answer? I don't think someone, even if they are an Expert, should be able to choose their answer as the best answer. Is there some setting for this so that only other people can choose your answer?
BTW, I'm using version 1.5 beta 2 and in my set up only Experts or higher can answer questions and only Experts or higher can choose the best anwer.