I find it odd that they had completed a good portion of their trip, including several dangerous hikes (during which at any time he could have pushed her and made it look like an accident). If something sinister had been planned, then you’d think it would have happened a little earlier on during one of the hikes. Or that he wouldn’t have fully agreed with documenting the entire trip, which would really kind of screw up any “plans” due to making it obvious when she stopped posting. This is all very strange.