Individual SharePoint documents are always restored to SharePoint document libraries as checked out to the credentials specified by the logon account used for the restore. The documents must be checked in or published by that user before others can use them.
If you try to restore over a document that is published or checked in, the restore will fail. If you try to restore over a document that is checked out, the restore will fail if the document is checked out to a user that differs from the logon account credentials used for the restore.