why does bosh update uaa_z1 when trying to recreate uaa_z2

gistfile1.txt

Task 7076 done

+------------------------------------+---------+---------------+-------------+
| Job/index                          | State   | Resource Pool | IPs         |
+------------------------------------+---------+---------------+-------------+
| api_worker_z1/0                    | running | small_z1      | 10.10.16.36 |
| api_z1/0                           | running | large_z1      | 10.10.16.38 |
| clock_global/0                     | running | medium_z1     | 10.10.16.45 |
| consul_z1/0                        | running | small_z1      | 10.10.16.30 |
| consul_z2/0                        | running | small_z2      | 10.10.80.30 |
| consul_z2/1                        | running | small_z2      | 10.10.80.31 |
| doppler_z1/0                       | running | medium_z1     | 10.10.16.47 |
| etcd_z1/0                          | running | medium_z1     | 10.10.16.13 |
| etcd_z1/1                          | running | medium_z1     | 10.10.16.28 |
| etcd_z2/0                          | running | medium_z2     | 10.10.80.12 |
| hm9000_z1/0                        | running | medium_z1     | 10.10.16.46 |
| loggregator_trafficcontroller_z1/0 | running | small_z1      | 10.10.16.48 |
| nats_z1/0                          | running | medium_z1     | 10.10.16.4  |
| router_z1/0                        | running | router_z1     | 10.10.16.8  |
| runner_z1/0                        | running | runner_z1     | 10.10.16.42 |
| runner_z2/0                        | running | runner_z2     | 10.10.80.40 |
| stats_z1/0                         | running | small_z1      | 10.10.16.40 |
| uaa_z1/0                           | running | medium_z1     | 10.10.16.39 |
| uaa_z2/0                           | failing | medium_z2     | 10.10.80.36 |
+------------------------------------+---------+---------------+-------------+

VMs total: 19
Deployment `cf-diego'

Director task 7077

Task 7077 done

+--------------------+---------+------------------+--------------+
| Job/index          | State   | Resource Pool    | IPs          |
+--------------------+---------+------------------+--------------+
| access_z1/0        | running | access_z1        | 10.10.16.62  |
| brain_z1/0         | running | brain_z1         | 10.10.16.113 |
| cc_bridge_z1/0     | running | cc_bridge_z1     | 10.10.16.115 |
| cell_z1/0          | running | cell_z1          | 10.10.16.114 |
| database_z1/0      | running | database_z1      | 10.10.16.112 |
| route_emitter_z1/0 | running | route_emitter_z1 | 10.10.16.116 |
+--------------------+---------+------------------+--------------+

VMs total: 6
Deployment `concourse'

Director task 7078

Task 7078 done

+-------------+---------+---------------+-------------+
| Job/index   | State   | Resource Pool | IPs         |
+-------------+---------+---------------+-------------+
| discovery/0 | running | discovery     | 10.10.16.51 |
| web/0       | running | web           | 10.10.16.52 |
| worker/0    | running | workers       | 10.10.16.54 |
| worker/1    | running | workers       | 10.10.16.53 |
+-------------+---------+---------------+-------------+

VMs total: 4
Deployment `identity_service_broker-aws'

Director task 7079

Task 7079 done

No VMs

/development/pivotal/cloudfoundry/cf-release(identity-latest) $ bosh recreate uaa_z2
Acting as user 'admin' on deployment 'cf' on 'microbosh'
You are about to recreate uaa_z2/0

Detecting deployment changes
----------------------------
Releases
No changes

Compilation
No changes

Update
No changes

Resource pools
No changes

Disk pools
No changes

Networks
No changes

Jobs
uaa_z1
  instance_states
    - 0: recreate

Properties
No changes

Meta
No changes

Cannot perform job management when other deployment changes are present. Please use `--force' to override.
/development/pivotal/cloudfoundry/cf-release(identity-latest) $ 
/development/pivotal/cloudfoundry/cf-release(identity-latest) $ bosh download manifest cf /tmp/cf.yml 
Acting as user 'admin' on deployment 'cf' on 'microbosh'
Overwrite `/tmp/cf.yml'? (type 'yes' to continue): yes
Deployment manifest saved to `/tmp/cf.yml'
/development/pivotal/cloudfoundry/cf-release(identity-latest) $ bosh recreate uaa_z2
Acting as user 'admin' on deployment 'cf' on 'microbosh'
You are about to recreate uaa_z2/0

Detecting deployment changes
----------------------------
Recreate uaa_z2/0? (type 'yes' to continue): yes

Performing `recreate uaa_z2/0'...

Director task 7080
  Started unknown
  Started unknown > Binding deployment. Done (00:00:00)

  Started preparing deployment
  Started preparing deployment > Binding releases. Done (00:00:00)
  Started preparing deployment > Binding existing deployment. Done (00:00:01)
  Started preparing deployment > Binding resource pools. Done (00:00:00)
  Started preparing deployment > Binding stemcells. Done (00:00:00)
  Started preparing deployment > Binding templates. Done (00:00:00)
  Started preparing deployment > Binding properties. Done (00:00:00)
  Started preparing deployment > Binding unallocated VMs. Done (00:00:00)
  Started preparing deployment > Binding instance networks. Done (00:00:00)

  Started preparing package compilation > Finding packages to compile. Done (00:00:00)

  Started preparing dns > Binding DNS. Done (00:00:00)

  Started preparing configuration > Binding configuration. Done (00:00:09)

  Started updating job uaa_z1 > uaa_z1/0 (canary)