To simply say that the speaker must be lying in either part 1 or 2a/b doesn't satisfy the fact that it can be considered a true paradox rather than a physical error whether intentional or not. Consider, that part 1 is just an affirmation of something which is recognised to be true. part 1 is affirmed by the speaker as a statement to alert others to a form in which they would understand. such as; "it is raining." part 2 then simply has to be the affirmation of what the speaker believes to be true rather than a conveyed message of indication.