(Also got "ffs_blkfree: freeing free block" panic when trying to do "rm -rf /home/lost+found")

[Tinker]

After rebooting the machine (now in ordinary softdep mode, and fsck did 
its job), I tried to do "rm -rf /home/lost+found", and got "ffs_blkfree: 
freeing free block".

Find photo of panic screen attached here, with indefinite storage: 
http://picpaste.com/Crash-0Lj3JJ2r.jpg .

I'm not so freaked out by this error as indeed my FS must have been in a 
badly inconsistent state, however, nonetheless I guess this is a bug.