I would suspect the admin went to remove the dn from a specific phone, but accidently hit delete, so it purged it from all devices.
Sr. UC Engineer
World Wide Technology
From: email@example.com [mailto:firstname.lastname@example.org] On Behalf Of Rick Gilliam
Sent: Monday, June 18, 2012 7:26 AM
To: cisco voip
Subject: [cisco-voip] CM 8.X 6.18.2012
Has anyone experienced a Call Manager deleting Dn's without Admin Assistance?
curious behavior with 8.0.3