CURRENT r250636: ZFS pool destroyed while scrubbing in action and shutdown

Several machines running 
FreeBSD 10.0-CURRENT #0 r250636: Tue May 14 21:13:19 CEST 2013 amd64
were scrubbing the pools over the past two days. Since that takes a
while, I was sure I could shutdown the boxes and scrubbing will restart
next restart automatically.

Not this time! On ALL(!) systems (three) the pools remains
destroyed/corrupted showing this message(s) (as a representative, I will
present only one):


zpool status

  pool: ASGARD00
 state: FAULTED
status: The pool metadata is corrupted and the pool cannot be opened.
action: Recovery is possible, but will result in some data loss.
        Returning the pool to its state as of Wed May 15 08:36:02 2013
        should correct the problem.  Approximately 7 seconds of data
        must be discarded, irreversibly.  After rewind, several
        persistent user-data errors will remain.  Recovery can be
attempted
        by executing 'zpool clear -F ASGARD00'.  A scrub of the pool
        is strongly recommended after recovery.
   see: http://illumos.org/msg/ZFS-8000-72
  scan: none requested
config:

        NAME                                            STATE     READ
WRITE CKSUM
        ASGARD00                                        FAULTED      0
0     1
          raidz1-0                                      ONLINE       0
0     8
            gptid/1e716118-1492-11e2-b828-90f6526a24d6  ONLINE       0
0     0
            gptid/294a6798-1492-11e2-b828-90f6526a24d6  ONLINE       0
0     0
            gptid/30c813f8-1492-11e2-b828-90f6526a24d6  ONLINE       0
0     1
        logs
          ada0p1                                        ONLINE       0
0     0


This happened on all systems. Another ZFS pool has only one disk, it
also happened to fail and being corrupt.