Gotham Central wrote:
The problem is that it could not have been 1996 when the Doctor crashes. When the TARDIS is flying over London the Millennium Dome and London Eye are clearly visible. The Eye was completed in 1999 and the Dome in 2000.
According to the DVD commentary on The Eleventh Hour
, that opening teaser was originally intended to take place in 1996, but it wasn't until the editing stage that they noticed that the Dome and the Eye shouldn't have been there, but Moffat reasoned that the TARDIS simply goes back in time before crashing in Amelia's garden. So, it's essentially a production mistake, but there's such an obvious explanation for it that the production team didn't waste time worrying about it.