A D stock train - the trains that were used on the District Line at the time of filming
The train seen in the movie - a 1996 stock, not a D stock!
Skyfall used 1996 stock for filming trains on the District line, but in real life, 1996 stocks have never ran on District tracks, and vice versa. The reason for the difference is due to the filming location, Charing Cross, only being able to hold deep-level trains (like the '96) and not being able to hold sub-surface trains (like the D stock). It's an issue 99% of people will gloss over, but something that is a pretty obnoxious issue to me, given that it's 2 different types of train, but I obviously understand the reasons why the filmmakers did what they did.
Bond supposedly chases the train from Vauxhall (Where MI6 headquarters is) to Westminster, before his journey is rudely interrupted by an explosion. Westminster is on the District line. but Vauxhall is not. It's on the Victoria line. So, Bond must have either had to change trains or boarded at a different station to have a one-seat ride, which aren't things that happen in the movie. As such, the map doesn't really make sense.
For those who actually care about the realness of the trains in Skyfall, I've devised a solution. The chase begins in Vauxhall, like it does in the movie, but instead of the District, Bond hops on the Victoria, a line that actually stops there. He takes the Victoria to Green Park, where he changes for the Jubilee line. This would give him the opportunity to do more Bond antics in the station, and maybe show a bit of Buckingham Palace (Green Park is the closest station to it, But St. James' Park is nicer to use for it in my opinion). Bond then takes the Jubilee to Westminster, but instead of an explosion, the train is suddenly rerouted into the abandoned platforms at Charing Cross, leading to the same chaotic event. Since Green Park and Charing Cross are very similar architecturally, the scene filming would make sense in that regard, and the 1996 stock would be accurate as well, since they are used on one of the lines that Bond rides on. The end also calls back to the real location and one of London's lost stations, getting people interested in the railways beneath them. I know this is an exercise in futility since the movie was released over a decade ago, but it's still something that I'd like to write about, and it's my website as well. It says so on the bottom!