BRMS: Why is it saving QUSRBRM on a CHGMEDBRM command?

I have a control group which looks like:
Backup
Seq Items Exit command

10 *EXIT addlible routines
20 ROB
30 *EXIT ROUTINES/FTP400CMD RMTSYS(GDIHQ2) INFILP(N)
QINFIL(GDWEB/FTPIN) INMBR(VRTCLG)
40 *EXIT CHGMEDBRM VOL(VRT001) EXPDATE('01/01/01')
50 *EXIT CHGMEDBRM VOL(VRT002) EXPDATE('01/01/01')
60 *EXIT SNDMSG MSG('Backup is complete on GDWEB') TOUSR(rob)

Item 20 is a
CHGLNKLBRM ?*LIST(ROB)
?*TYPE(*BKU)
OBJ(('/rob' *INCLUDE))
TEXT('test backing up the /rob directory')

Ran successfully, however upon completion I noticed that one of the
volumes was still active and not expired. So I did a DSPLOGBRM and I
noticed that after it expired those two volumes it saved QUSRBRM off. I
can see it doing that after the link save but can't fathom why it's doing
it after the expiring of the volumes.
1/16/12 15:54:58 Volume VRT002 expired.
1/16/12 15:54:58 Volume VRT002 changed.
1/16/12 15:54:59 Change to media controls successful.
1/16/12 15:54:59 Change to media controls successful.
1/16/12 15:58:40 12653 blocks processed for sequence 1, volume VRT002,
on
1/16/12 15:58:41 19 objects saved from library QUSRBRM.
1/16/12 15:58:42 Save of BRM media information at level *OBJ complete.
1/16/12 15:58:43 Control group XQP02TEST type *BKU processing is
complete.
1/16/12 15:58:43 SNDMSG MSG('Backup is complete on GDWEB') TOUSR(rob).

Work with Media Information
Saved Save Save Save Parallel Volume File Expire
Item Date Time Type Devices Serial Sequence Date
QUSRBRM 1/16/12 15:55:04 *QBRM VRT002 1 1/17/12


High level perspective:
I am trying to save a directory off to virtual tape using BRMS. Then I
ftp the virtual image catalog entries to a machine local to us where we
can mount tapes and get those to Iron Mountain.

Rob Berendt