Rollback imports data

If I run a user migration using migrate_d2d, whenever I rollback the migration via drush, the migration rolls back then re-runs (so user accounts are deleted and recreated). If I rollback via the Migrate UI, it rolls back correctly and deletes the user accounts.

16:05:22 jonathan:~/Sites/example.local (master) $ drush ms
 Group: example  Total  Imported  Unprocessed  Status  Last imported       
 ExampleUser     117    0         117          Idle    2015-07-23 16:00:07
 
16:05:27 jonathan:~/Sites/example.local (master) $ drush mi ExampleUser --limit=3
Processed 4 (3 created, 0 updated, 0 failed, 1 ignored) in 0.2 sec (1171/min) - done with 'ExampleUser'                                    [completed]

16:05:39 jonathan:~/Sites/example.local (master) $ drush mi ExampleUser --limit=3 --rollback
Rolled back 3 in 0.1 sec (3218/min) - done with 'ExampleUser'                                                                              [completed]
Processed 4 (3 created, 0 updated, 0 failed, 1 ignored) in 0.1 sec (1686/min) - done with 'ExampleUser'   

16:07:38 jonathan:~/Sites/example.local (master) $ drush ms                                                                          
 Group: example  Total  Imported  Unprocessed  Status  Last imported       
 ExampleUser     117    114       0            Idle    2015-07-23 16:06:41