Yeah, I probably could have explained them more. It's hard to know exactly how much someone won't know about something you do know.
The logic is like this: if a character was the detective of the story, would the story be violating any of Knox's rules? If so, which one.
So, the obvious example is the 7th rule, "The detective must not himself commit the crime": if the murderer was the detective, then the story would be violation the 7th rule, which therefore means that the murderer, in this case the player, isn't the detective. I think this would have been a good, easy tutorial for the player, but I didn't have enough time to implement it.
Glad you enjoyed it.