Juju fails to destroy-environment with wipe enabled: Node cannot be released in its current state ('Disk erasing').

Using MAAS trunk (revision 3302) and juju 1.18.4+dfsg-0ubuntu0.14.04.1 (in trusty-updates):

To recreate:
- Configure MAAS to "Erase nodes' disks prior to releasing."
- Bootstrap an environment and wait until the bootstrap node is 'Deploying' (and has been booted up);
- Abort the bootstrap operation.

 juju bootstrap
Launching instance
WARNING picked arbitrary tools &{"1.18.4-trusty-amd64" "https://streams.canonical.com/juju/tools/releases/juju-1.18.4-trusty-amd64.tgz" "992e4244874ffec4af083cdeb58040420320f63ac6a3f7526c81d963fa4e53d6" %!q(int64=7389403)}
 - /MAAS/api/1.0/nodes/node-c35a1bdc-4b04-11e4-b919-eca86bfdb3be/
Waiting for address
Attempting to connect to nuc2.maas:22
Attempting to connect to 192.168.10.75:22
^CInterrupt signalled: waiting for bootstrap to exit
ERROR bootstrap failed: interrupted
Stopping instance...
Bootstrap failed, destroying environment
ERROR Bootstrap failed, and the environment could not be destroyed: gomaasapi: got error back from server: 409 CONFLICT (Node cannot be released in its current state ('Disk erasing').)
ERROR interrupted

This is the apache log:

192.168.10.2 - - [27/Oct/2014:17:50:01 +0100] "POST /MAAS/api/1.0/nodes/node-b6ea27ca-4b04-11e4-b919-eca86bfdb3be/?op=release HTTP/1.1" 200 698 "-" "Go 1.1 package http"
192.168.10.2 - - [27/Oct/2014:17:50:02 +0100] "DELETE /MAAS/api/1.0/files/fa0413fb-f0ae-44d3-895d-a29fbbef5ac3-provider-state/ HTTP/1.1" 204 216 "-" "Go 1.1 package http"
192.168.10.2 - - [27/Oct/2014:17:50:02 +0100] "GET /MAAS/api/1.0/nodes/?agent_name=fa0413fb-f0ae-44d3-895d-a29fbbef5ac3&op=list HTTP/1.1" 200 706 "-" "Go 1.1 package http"
192.168.10.2 - - [27/Oct/2014:17:50:02 +0100] "POST /MAAS/api/1.0/nodes/node-b6ea27ca-4b04-11e4-b919-eca86bfdb3be/?op=release HTTP/1.1" 409 297 "-" "Go 1.1 package http"

As you can see, the node is released *twice* and the second 'release' operation operates on a 'disk erasing' operation. That's the part that breaks.