Although there are different levels of canon, this does not mean relevant information cannot be included in situations where there are conflicting canon sources. Ambiguous continuity should always be noted. If an "official" canon source has been chosen, (e.g. Philip Pullman has said that a fact was a mistake and it was meant to be something else), the information from the conflicting source should still appear in the article in the extras section. Basically put, everything is canon unless specifically contradicted by a "higher" source.