All it takes is one searcher to sneeze (with their eyes closed), or look to the right when they should be looking left,or not be able to look under some dense bushes… if they did not do a structured grid search where you literally stand arms extended, hands touching, and cover every square inch, people are missed, sadly. We’ve seen it here repeatedly where someone’s remains are found by a hiker or hunter. Possible they did look at that exact spot but bones were moved by animals. Even a few feet makes a difference and in that terrain sadly I don’t see how it would have been possible to look at every square foot.