That's an excellent point, poettess. I haven't as yet read far enough to have noticed it. (Or perhaps I missed the correlation.) But I now recall at the end of Chapter 5 on page 73, the scene in which Navidson is playing with his daughter. She asks him to play a game called "always," and he asks what it is, but does not wait for an answer.
The last two lines on that page are:
I wonder if I've missed a previous example.