7. Why Doesn't The Eleventh Doctor's Screwdriver Look Like The One He Gave To River?
In 'Silence in the Library', Moffat established a set of parallels between River and the Doctor that would run throughout Eleven's tenure: River was a time traveller too, with a blue diary rather than a blue box, but with a sonic screwdriver to (nearly) match the Tenth Doctor's. But it was the Doctor claimed that it was his future screwdriver. Yes, the Doctor lies, but not about things that he doesn't actually know. He didn't know for certain it was his screwdriver, and it's more than possible that this was one that Eleven designed specifically for River. Maybe the Tenth Doctor created the screwdriver as soon as he got back in the TARDIS and the encounter with River was fresh in his mind. Maybe we've seen the design of the Twelfth Doctor's screwdriver already. Or maybe the design team felt like creating one more in the vein of Matt Smith and not just giving him Tennant's cast-offs.