A Dtrace of the EvFsaArchivingTask process on the EV server will show the following when the file is processed.
Hardcoded Processing Rule Failure, reason: The file: \\?\UNC\Fileserver.EV.LOCAL\Volume\Folder\SubFolder\47AD432B.doc will not be archived as it is a temporary file.
For more information on Dtrace refer to the Related articles section.
Bases on the hardcoded processing rules, by default, EV does not archive files that have a Temporary attribute applied.
Below is an example of how the attribute 'T' is shown under file properties > Details tab via Windows explorer.

If it is necessary to archive the file, the Temporary attribute will have to be removed so that EV can process the file for archiving.