You do also recall the unprocessed ballots being ‘found’ in unsecured areas in the Minnesota U.S. Senate race, right?
That's the reason I did the search for info. Seems to me that if these are indeed empty absentee ballots, would be easy to get them into the system UNLESS the election officials were diligent in checking the numbers with the applications.
If I remember correctly, you sign the application but you don't sign the absentee ballot itself.