Restriction Type on Audit Trail

Hi Gurus

I've enabled Audit Trail on Contact BC with 10 Fields with Restriction Type as 'No Restriction' and enabled New, Update & Assoc Audit. (But not enabled the Delete Audit).

Now to track delete event for SADMIN user I created a new Audit Trail BC record with BC as Contact, 2 fields, Restriction Type as User and enabled all auditing (New, Update, Delete, Assoc).

My expected behavior was that whenever a contact is deleted by SADMIN login (RCR in our case) delete audit log should be captured.

But no audit records for delete event was created.

I am unable to find any documentation which says that this should not work. Please throw some light! Thanks. We are currently using Siebel IP2014.