Factual error: There are a lot of comments about the Harrier (technically speaking it is an AV-8B, a slightly different aircraft) flown by Arnold Schwarzenegger, but everyone's missed the obvious one. The terrorist with the AK47 is unaware of the fact that a Harrier is hovering just outside the window until he slowly turns and see it there. He does a double take when he sees the Harrier just five metres away! A Harrier is an incredibly loud aircraft; you can hear them from three kilometers away. At that range the floor would shake with the noise and he would have been in no doubt whatever that he had been under attack for some time.
Factual error: At the start, when Schwarzenegger leaves the party to steal the computer evidence, when he turns on the computer you can clearly hear the Macintosh start up sound, but when he looks at the computer screen it is the Windows loading screen. It's not a case of changing the sound files - PCs make no noise before Windows is fully loaded except perhaps the initial beep.
Factual error: Throughout the entire movie, Arnold and Tom are always riding in the GM S-series SUV. The thing about these vehicles is that they came with different side view mirrors and if you look close enough during all the shots with the SUV, the side mirrors on the side change, from small ones to big square ones, showing that two different GM S-series SUVs were used throughout the movie.
Factual error: Further to the comment about the loudness of the Harrier, Schwarzenegger flies one without ear protection of any kind. I was fifty metres from one at the Farnborough Air-show, and I can tell you that after landing he (and his daughter) would be both stone deaf. Yes, they are THAT loud.