Comment 4 for bug 1600031

Bingo:

https://review.openstack.org/#/c/335697/2/nova/compute/api.py@1677

That assumes that if the instance is in error state it should be a local delete, but this test that's triggering it is resetting the instance into error state:

http://git.openstack.org/cgit/openstack/tempest/tree/tempest/api/compute/servers/test_delete_server.py#n141

Even though it's got a host.