Exchange 2007 SP3, Update Rollup 10
User A works between her iPhone 5, iPad, and Windows7/Outlook 2013 machine to create and accept appointments on behalf of user B (delegated send-as permission).
User A creates an appointment through Outlook 2013 and invites User B at 12:55PM
User B accepts appointment through Outlook 2010 and sends response at 12:58PM
User A and User B both receive an appointment cancellation request for the appointment at 10:57PM, appears to generate from User A.
User A claims to have not been on any of her devices.
The cancellation notice cannot be found at all through Exchange message tracking.
The same situation plays out when the appointment is created from the iPad as well. The cancellation is sometimes sent within minutes.
I've pulled a trace log on appointment changes, but need help in analyzing it.