close consistency check failure

I recently added tablet server admin shutdown to the Concurrent randomwalk test.

After an hour, the following table problem appeared:

10 12:00:21,755 [tabletserver.Tablet] ERROR: Data file in !METADATA differ from in memory data !0;!0<<  

Note that this is the root tablet, so some other process was updating the files behind this server's back; I suspect inconsistent assignment.