Free choice

I read the rabbi’s book and the rabbi’s argument that if it is the Karaite, it is not free choice, and if it is a cause and effect, it is also contradictory, and I did not understand the rabbi’s response, which ignores a third party and the rabbi did not explain the party.
Every MNM argument ignores being a third party because only two sides can be understood and those who want to interpret the MNM need to explain the third side, and in the case of Didan, I understand only two possibilities. If we follow step by step in the stage that is the path from information to decision, there are two possibilities. I would be happy if the Rabbi would explain this to me. Thank you.