If one of the search results is for a document, there is no way to select that document, only the enclosing page. If I've got a page that contains multiple documents (such as monthly police reports, audits, etc.) going to the enclosing page does me no good, as I have no idea which document contains the text. In addition the search result itself shows some of the text in the document that matched, so I should be able to click on that and go directly to the document.
To have to essentially a dummy enclosing page for each document just to make the search results functional seems wrong. It requires an additional click to get to the document I want, and forces the site design to adhere to a backend design decision.