Retaliation can be a beotch! But, as AA's history shows, it's not limited to just the pilots either!
However, in defense of AA (I must) if the company has a policy regarding uniforms, it should be able to enforce it, but only through proper channels. I don't believe this pilot's opinion would have carried any less weight had he appeared in a three piece as opposed to an official company uniform. The pilot had balls, I'll give him that!