MarkB
Legend
The other question this episode raised was about the TARDIS and the Doctor. In The Doctor's Wife, the TARDIS said she picked the Doctor but in this episode Clara actually got teh Doctor to choose her yet the TARDIS doesn't like Clara? I know Clara is an abberation in the future (which the TARDIS can "see") but without her the TARDIS would have been decommissioned long ago.
As I understand it, the likely explanation is that the TARDIS originally did choose the Doctor, but the Great Intelligence went back and diverted him to a different TARDIS, and then Clara went back and undid that diversion by guiding him back to the right TARDIS.