I think this point of contention we are having was already an issue in episode 3. I don't really think this makes things worse. Before the show, Obi-Wan's final confrontation on Mustafar already made the scene in episode 6 feel awkward. I think, and this is unfortunate, the audience is supposed to believe that Ben is a bad narrator all the way through the whole trilogy, including ep 6 with his discussion with Luke. As such, if we were to make sense of this, Ben has to be lying to Luke regarding the: "hidden from your father" thing, which is bizarre since it's such a weird thing to lie about.