The quote from Concrete Jungle is actually correct. A computer that has no external connections is immune to remote hacking, but as long as there's actually physical access to it, hacking is possible — even if that hacking consists of something as tedious as opening up the case and making physical modifications to the system.

Pulled the following from the Eleventh Hour entry:

• (possibly justified since if it was 12 years since meeting Amelia in her backgarden and that happened in 2010 then it should be 2022 by then).
  • But who says that happens in 2010? It's more likely that that happened in 1998, and the later meeting is in 2010. And this isn't even an electronic clock that might be in radio-contact with Greenwich, it's a mechanical clock.
    • Doctor Who Adventures says the meeting with Amelia was 1996, the bulk of the episode was 2008, and Amy finally leaving with the Doctor is 2010.

"Flesh And Stone" firmly confirms the DWA theory: Amy left with the Doctor on 25th Jun 2010.