After marveling at this thread, it occurred to me that there should be a limit on self-answers on non-wiki questions. This is mainly to protect the user from themselves so they can only use comments to respond, not inadvertantly spam the answer list.
Obviously, the user is not a native English speaker, so s/he may not get the subtle difference between a comment and an answer. If coming from the forum world, that shiny text box at the bottom of the post is the only way to respond.
Edit: Following Kyle's comment: How about a way for a mod to turn an answer into a comment?