Spoilers
I have a problem, I took the route of Koku, I had answered all the questions correctly up to a certain point, even with the medical evidence.
But then comes the point where it doesn't go any further, and then I took question five and then I took the bullet as proof and then I took question six, which didn't help either, and then I did the same thing again in reverse.
Then I had a quick look at the guide the developer posted here, right up to this point, only I looked at it and didn't do anything wrong.
This is a bug ? that is triggered by the game and prevents it from continuing.