>>56769837The book exchange isn't even proof.
If it's a loop, he can just pick it up. Because the White Book means that he will have to go and meet Terapagos to advance his research. And each time, he does things that disrupt the timeline. Recovering the book is possible in a loop context.
The notes do not detail everything that happened during the meeting, nor that the book was written by Briar. This is not to say that all of these events ever happened. The goal of the notes is to push the player to go to the lake, to discover this scene. They're not going to spoil anything that happened. So you cannot know whether or not the book exchange took place in the past.
Either it never happened and we're set.
Or it happened, but never got it back.
Either it took place, and he found it, which feeds a potential loop.