Capturing rowcounts when using Composable DML

/******************************************************************************************************************************
A solution to the problem outlined at http://pastebin.com/5wBsTVx9, that rowcoutns cannot be captured when using Composable DML

Jamie Thomson, 2013-02-07
******************************************************************************************************************************/

/*Setup table first and insert some data into [src]*/
USE tempdb
IF OBJECT_ID('src') IS NOT NULL     DROP TABLE src;
CREATE TABLE src (
    id      INT
,   name    NVARCHAR(MAX)
);
IF OBJECT_ID('tgt') IS NOT NULL     DROP TABLE tgt;
CREATE TABLE tgt (
    id      INT
,   name    NVARCHAR(MAX)
);
/*[updates] will be used as the target of the Composable DML insertion*/
IF OBJECT_ID('old_values') IS NOT NULL      DROP TABLE old_values;
CREATE TABLE old_values (
    id      INT
,   name    NVARCHAR(MAX)
);
IF OBJECT_ID('mrgout') IS NOT NULL      DROP TABLE mrgout;
CREATE TABLE mrgout (
    action_         NVARCHAR(MAX)
,   inserted_id     INT
,   inserted_name    NVARCHAR(MAX)
,   deleted_id      INT
,   deleted_name    NVARCHAR(MAX)
);
INSERT src(id,name)VALUES(1,'don'),(2,'kaina');
GO

/*Everything after here gets run twice because the batch ends with GO 2*/
TRUNCATE TABLE mrgout;
INSERT mrgout(action_, inserted_id, inserted_name,deleted_id, deleted_name )
SELECT  mrgout.action_
,       mrgout.inserted_id
,       mrgout.inserted_name
,       mrgout.deleted_id
,       mrgout.deleted_name
FROM    (
        MERGE   tgt
        USING   src
            ON  tgt.id = src.id
        WHEN MATCHED THEN
            UPDATE
            SET tgt.NAME = src.NAME
          WHEN NOT MATCHED THEN
            INSERT(id,name)
            VALUES(src.id,src.name)
        OUTPUT $ACTION AS action_
        ,       INSERTED.id AS inserted_id
        ,       INSERTED.NAME AS inserted_name
        ,       DELETED.id AS deleted_id
        ,       DELETED.name AS deleted_name
        )mrgout
;
INSERT  dbo.old_values(id,name)
SELECT  deleted_id,deleted_name FROM mrgout
WHERE   mrgout.action_ = 'UPDATE' --Filtering on $action=UPDATE allows us to get the replaced values from DELETED virtual table
SELECT  [INSERT_@@ROWCOUNT]=(SELECT COUNT(*) FROM mrgout WHERE action_ = 'INSERT'),[UPDATE_@@ROWCOUNT]=(SELECT COUNT(*) FROM mrgout WHERE action_ = 'UPDATE'),row_tally_in_tgt=(SELECT COUNT(*) FROM tgt)
GO 2