I think that was explained by the Doctor rather well.. He did ask which war was it, because he had seen so many. There could easily have been others with similar mixes of high/low tech on other world.
Point taken, but couldn't the TARDIS have given him some indication as to where he was? AFAIK, that planet has not been repeatedly relocated in space...
What do you all think about the yet-again re-jigged presentation of Clara here? We don't know how much time elapsed between this story and "Last Christmas", but it seems like she and the Doctor have been apart again for a while. And yet, she now seems to be
acting as the Doctor's proxy on Earth when he's not around. She seems much more mature, more hard-edged, and has insight into the the Doctor's way of thinking and doing things that very few, if any, other companions have ever had. At first I thought this was just another step in the continuing Mary Sue-ification of the character, but then I considered who the episode's villain was, and remembered
his previous monologue about how the Doctor molds his companions into a proxy army. In Clara's case, it certainly seems to have worked. Though that theme would've been more in keeping with last season. cheers,
Gabe