Ouch. Thanks for the heads up, Tammie.
I've not observed it, but will watch out for this behavior. As you are certain the copies did exist, I'd expect some type of residual audit trail confirming their deletion, whether it was a user, or a back-end process that caused it.
Perhaps they are in the recycle bin, or you might find evidence in a Notes report or one of the built-in audit reports?
Regards,
Doug