The FHIR Document Reference includes DocumentReference.context that describes
“The clinical context in which the document was prepared.”
“These values are primarily added to help with searching for interesting/relevant documents.”
“The time period over which the service that is described by the document was provided”
So you know the clinical time of the document, as opposed to just when it was written, or indexed etc., which may be more recent.
There is also a link to the Encounter, so you can see the care itself. This could be used in theory to see if there were other encounters about the same thing, which may be better sources of documentation.
Re “partial”, DocumentReference also has a “docStatus” that says if the content is preliminary or final etc in terms of workflow.