Howling:Not 11's Tardis

Please accept my apologies if this has already been discussed ad nauseum, but I was wondering about the different appearance of the Tardis that caught River Song as she escaped from The Byzantium in 'The Time of Angels'.

A close look at the front of The Tardis shows that it doesn't bear the St John emblem that was restored after 10's Tardis regenerated into the current version. Was this just a production error or could it possibly be part of the plot that will be explained during the finale of series 5? ChrisL 13:53, June 10, 2010 (UTC)