If the restore had been COMPLETEly successful, ADSM would have gone ahead
and deleted the volume (i.e., returned it to scratch) when the RESTORE
completed.  So there must be some data left on it.

First list the contents and see what is there.  Then I would try a MOVE DATA
one more time, just to see if you can read any of what is left.  Then if you
are sure you can't get that data back, do the DELETE VOLUME DISCARDDATA=YES,
understanding that you no longer have backups of those things in the
CONTENTS list.

If you got the original error while reading the label, then by all means,
relabel it; you will also have to specify OVERWRITE=YES on your label libv
command.

But if the original error was down in the middle of the tape, relabelling
probably won't do anything for you.  I would just check it back in as
SCRATCH, let TSM write over it again.