I don't have a specific answer for you on this one, as to why they would have been removed, but what we realized is that the access to the shared drive where all the documents are kept is not necessarily protected access. Internally, a lot of people would have access to the same file, so people can go there.
What we realized is that there is also a link between different agreements. Sometimes the documents were there, but then they were moved to another agreement, because they saw a link there from the program manager's perspective. We are looking into restricting access when documents are filed on a specific folder so that they are not moved anymore.