PDF "is damaged and can't be opened" on mounted drive
When this happens to me, I delete the ._results.pdf file, and then I can open it from the mounted directory.
This is related to Files wrongly considered as damaged in encfs volume and probably this bug: https://github.com/osxfuse/osxfuse/issues/162 - so upgrading to a newer version of sshfs should work, but I've found that it works if you start sshfs with -o allow_root, so
sshfs -o allow_root hostname:path mountpoint
Hope that helps!