In the r12.8 CF3 Server patch we made a change to how we audit no approval workflow type events. These are events where a user requested access to an account where there is no approval needed. If the request is for a future time an event is generated called 'Grant Access to Account Event' which gives the access. Before CF3 these events we seen listed as the default approver such as the system manager user. However, since these are no approval required events this was incorrectly being audited. So we made a change so that the user is now seen as unknown to designate that no one approved it as it wasn't required.