How To Force Deferred Update To Create Two Rows In Change Data Capture

I have located a bug in the functions cdc.fn_cdc_get_net_changes_<capture_instance> generated when you enable cdc on a table. This bug can be triggered if 2 rows are created in the _CT table having the same values for the __$start_lsn, __$seqval and the table's key column(s). From research on the internet I have found such rows can be created by a "deferred update": a single update statement in which a column that is part of a unique constraint is updated.

In order to report the bug with Microsoft I need to create a complete series of steps-to-reproduce. But even though the situation happens several times a day in our production environment, I have not yet been able to reproduce it in my test environment.I need a single update statement (plus maybe some steps in advance) that make that the log reader inserts 2 rows into the _CT table, one with __$operation = 1 (delete) and another with __$operation = 2 (insert) as opposed to the single row with __$operation = 4 that it inserts for a normal update. Below is the script I have so far to create a fresh database, enable cdc, create a test table, insert some data and update this data.

I would have liked the last update statement to be handled as a "deferred update". However in all of my tests the log reader just simply inserts a single row into the cdc.dbo_NETTEST_CT table.how to reproduce the situation where I get the 2 rows with __$operation 1 and 2 from a single update statement instead of the single row with __$operation = 4.

CREATE DATABASE [cdcnet]
CONTAINMENT = NONE
ON PRIMARY
( NAME = N'cdcnet', FILENAME = N'S:SQLDATAcdcnet.mdf' , SIZE = 4096KB , FILEGROWTH = 1024KB )
LOG ON
( NAME = N'cdcnet_log', FILENAME = N'T:SQLLOGcdcnet_log.ldf' , SIZE = 1024KB , FILEGROWTH = 10%)

[code]....