docsTotal changed during rebalance

docsTotal decreased during rebalance. It was 1512, and became 1509:

2013-05-06 16:40:03 | INFO | MainProcess | MainThread | [rebalance_progress._check_stats] Checked stat: {u'172.27.33.10':

{u'activeVBucketsLeft': 0, u'docsTotal': 1512, u'docsTransferred': 1438, u'replicaVBucketsLeft': 0}

, u'172.27.33.11':

{u'activeVBucketsLeft': 176, u'docsTotal': 0, u'docsTransferred': 0, u'replicaVBucketsLeft': 24}

, u'172.27.33.12':

{u'activeVBucketsLeft': 176, u'docsTotal': 2524, u'docsTransferred': 1647, u'replicaVBucketsLeft': 24}

, 'bucket': u'default', 'buckets_count': 1}
2013-05-06 16:40:03 | INFO | MainProcess | MainThread | [rebalance_progress._check_stats] Checked stat: {u'172.27.33.10':

{u'activeVBucketsLeft': 0, u'docsTotal': 1512, u'docsTransferred': 1438, u'replicaVBucketsLeft': 0}

, u'172.27.33.11':

{u'activeVBucketsLeft': 176, u'docsTotal': 0, u'docsTransferred': 0, u'replicaVBucketsLeft': 24}

, u'172.27.33.12':

{u'activeVBucketsLeft': 176, u'docsTotal': 2524, u'docsTransferred': 1647, u'replicaVBucketsLeft': 24}

, 'bucket': u'default', 'buckets_count': 1}
2013-05-06 16:40:04 | INFO | MainProcess | MainThread | [rebalance_progress._check_stats] Checked stat: {u'172.27.33.10':

{u'activeVBucketsLeft': 0, u'docsTotal': 1509, u'docsTransferred': 1447, u'replicaVBucketsLeft': 0}

, u'172.27.33.11':

{u'activeVBucketsLeft': 173, u'docsTotal': 0, u'docsTransferred': 0, u'replicaVBucketsLeft': 21}

, u'172.27.33.12':

{u'activeVBucketsLeft': 173, u'docsTotal': 2524, u'docsTransferred': 1668, u'replicaVBucketsLeft': 21}

, 'bucket': u'default', 'buckets_count': 1}