remove-tree with conflicts leaves you with conflicts but no wt metadata

Example:

mbp@lithe% bzr st
unknown:
  bzrlib/tmp.diff
mbp@lithe% bzr di
mbp@lithe% bzr remove-tree
Conflict: can't delete bzrlib because it is not empty. Not deleting.
Conflict: can't delete bzrlib/benchmarks because it is not empty. Not deleting.
.....
bzr remove-tree 2.48s user 0.29s system 95% cpu 2.898 total
mbp@lithe% ls
bzrlib/
mbp@lithe% rm **/*pyc
mbp@lithe% bzr clean-tree
default2a plugin set default format to 2a
bzr: ERROR: No WorkingTree exists for "file:///home/mbp/bzr/430529-extension-warnings/.bzr/checkout/".
mbp@lithe% bzr st
default2a plugin set default format to 2a
bzr: ERROR: No WorkingTree exists for "file:///home/mbp/bzr/430529-extension-warnings/.bzr/checkout/".