dfsrdiag.exe backlog showing one nameless file?

When have a dfsr hub and spoke setup for a replicated folder.

The permissions were set on the spoke folders so no end users could modify the contents.

To my surprise, when running a health report on the hub, I found a few spokes had a single outbound file backlogged.

When I check the backlog with dfsrdiag.exe on the spokes I see one apparently nameless file:

F:\>dfsrdiag.exe backlog /ReceivingMember:dfsrhub /SendingMember:spoke123 /RGName:myRG /RFName:myRF

Member <dfsrhub> Backlog File Count: 1
Backlog File Names (first 1 files)
     1.

Operation Succeeded

When checking dfsrdiag.exe ReplicationState I see only 2 connections to other dfsr members (non of which are the servers in question).

Is this a bug? What is this?