I don’t recall that exact story, but there are many like it in his Missing 411 series.
I have all nine of Paulides books and a constant theme running through his books on people that went missing in the wilderness is that they “somehow got separated from their companions.” Most are never found, and the few that are often have no memory of how that got lost or what they were doing while lost. SAR members are often stumped when they can’t find these people.
I can say I’ve been to a place in the Navajo reservation mountains where it was so quiet in the middle of the day back in the 90s. No animals, no background activities. It was eerie. Now my friends and I were used to being out in the wilderness, but that’s the only time I experienced what David Paulides described in cases where people went missing that things went deathly still.
And another anecdote is my buddy from High school was rising an ATV with other family members on ATVs on a mountain trail. The last ATV rider says at one point something tugged on his rifle barrel- the rifle was on his back. He looked back and nothing was there. Check out the conversation at 14:40 on this link. They’re talking about the last man on the link disappears.
https://www.youtube.com/watch?v=IGNwRJuQ6zw&list=PLMDrCBp9ktoT-xeyD-cAwnolLOxEb7905&index=3st interesting.