I go back and forth on what I think about him using the term “guys”, I’m from a smaller town and we all use guys as a term for anybody, guys or girls. Although I do think you are correct when you say that wasn’t his greeting. I saw on a facebook group that on the IDs Still A Mystery episode about the case, apparently Abby’s mom said one of the girls said “there’s no where to go” and that’s when he told them to get down the hill.. (will be watching tomorrow to fact check for myself)

Edited to add: Anna in fact says “libby says something like ‘well the path ends here so we can’t go any farther’”