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
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/*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