I don’t attribute it to either of those things though!
I believe that, even assuming that they really were dating in his head, it is inconceivable that he did not once ponder the question of either confirming it in the text or leaving things murky.
eta: That is a basic level of storytelling competence that it is really safe to grant the guy, no matter how frustrated we might get about him writing his story Wrong or w/e, because otherwise we would never have gotten this far.