Not really, although it's a more careful reading than I expected. I think that would be a distinction without a difference. No, as with Gwern, I think the main issue here is you. What sort of person is Gwern training himself to be?
Like Gwern, you act like you're conducting a study on someone, but it's really just two people talking. Pretend, for a moment, the other person is actually much smarter than you and conducting a test of the exact same principle you are testing. In Gwern's case, that leads to a much more interesting interpretation of the incident, since he's clearly horribly biased (the test really does have a result). In your case, you're not at all truth-seeking. I would advise you seek to truth in your relationship with J first (either by self-modification or greater honesty of the unmodified)
Here's my frivolous question: How old are you and how old is J? (you can make it approximate if you think it would reveal personal info).
No, the pretense is not that they're trying to manipulate you in the other direction, but that they're manipulating your manipulation. That is, Gwern was being tested on his fairness as a experimenter of fairness. You are being tested on your truth-seeking as an experimenter in truth-seeking. Of course, you are, just not by J.
I had two reasons for asking about age (you're right on one). Your narrative sounded pretty juvenile even in its self-description. I was hoping that was true (for both your sakes).
Here's another game for you to play: Your brain learns whereof you know not. What general rules is it learning as you interact with J? Someday, if you're luck enough, you can plan on being quite slow. The virtues you currently rely on (roughly: quick-witted) will have left you. You should be investing as quickly as you can in cultivating other personal virtues. Don't plan on the world changing enough that that can be avoided. I can't seem to avoid a patronizing attitude (bad sign for me, similarly: I'm out).