Because I occasionally get email about this, a canonical, public reference to the question about that Fate-locked Carnival option can be found toward the bottom of this interview.
[Alexis Kennedy:] But this particular [bug] report was very polite and it went like this: “Dear Failbetter, I played through four-fifths of a story, until I reached the nightmarish midnight carnival, where I was offered a 40 nex opportunity to delete my character forever, with no advantage or unique text to gain. I thought I’d do it anyway because I was curious.” Now, bear in mind, that nobody is going to get this far with a starting character. But he went through with it and then wrote to us to say: “There must have been a glitch because my character wasn’t deleted. I hesitate to ask for the return of the Nex but could you please delete my character because I feel like I’ve got away with something.”
[Interviewer]: Did you? Delete it, I mean?
Kennedy: I think I gave him a unique quality as a badge of honour actually. “Your game failed to destroy my character after I paid it to!”