the weird route is accounted for by the prophecy I think, just never shown because it's Too Evil. why else would Mantle (the original game in chapter 3, which like everything is based on the prophecy) know of a forbidden path. it manifests as Kris' intrusive thoughts (john mantle accuses them of enjoying it) which spiral out of control. they're the one coming up with the dialogue options, they're prompting YOU for what to do, asking whether or not to do Evil (Proceed with the forbidden path) or play the game like Normal. or rather you're telling Kris to proceed with evil. perhaps they're aware of its existence as well due to conspiracy reasons and part of them wants to Do It Anyways. maybe Carol told them to do it.
it's crazy how right we are about everything though. they're saying no one has better theories than us, quite frankly, and people tell me all the time that my understanding of things, all of it, they tell me I understand everything much deeper, much much better than anyone else. quite frankly I don't think anyone knows as much about this as I do.