You can use the information provided here to work on offline and pages results cases in change detection.
When the Connector is offline or when Paged results is enabled and an initial search request is made but the page containing modified entry is not retrieved yet, multiple changes made to that entry are merged. In other words the Connector receives only one entry containing the results of all operations that have been applied on it.
In these cases when an entry is added and then deleted in Active Directory the Connector will report "delete" operation for entries that have not been added to the repository being synchronized with Active Directory. This is not a serious restriction because IBM® Security Directory Integrator's Delete Connector mode first checks if the entry to be deleted exists and if it does not exist, the "On No Match" hook is called - this is where you can place code to handle/ignore such unnecessary deletes.
Another scenario is when entry is added and then modified. In that case the Connector will report an "add" operation for that entry, and the entry will contain all the changes made to it after the adding.
In all other possible cases the return entry will contain all the changes and it will be tagged with the last operation made to it.