Revealing mistake: When the villain finishes his 1st appearance in the Pentagon's videowall (with the fake Eiffel Tower on the back), the screen turns black when he finishes his statement. However, when the camera turns to the Army men present, you can see the reflection of the villain's face on the glass.
Revealing mistake: The actor who plays Tom Breaker is quite easily the worst impersonator of a smoker. Clearly not at ease with holding a cigarette, he also doesn't ever appear to inhale the cigarette smoke either.
GalahadFairlightRevealing mistake: Look for the blatantly awful special effects when the main bad guy is falling into the flames.
Revealing mistake: When Ryback is fighting the grey-haired bad guy in the kitchen, the bad guy is losing and spots a meat cleaver on the counter. When he quickly picks it up, holding it at head level, you can see the cleaver blade wobbling from side to side. An obvious rubber prop.
Revealing mistake: Before Trillings and Gilder enter their passcode for the first time at ATAC there's a screen showing the codes already entered and the transfer completed before they've typed anything.
Revealing mistake: When Bobby opens the door to grab the CD from the computer look at his right hand, he already has the CD before he's taken it out of the computer.
Chosen answer: Dane's speech was for the benefit of the hostages, not mercs. (It could be assumed that they knew he was lying.) Near the end of the film, a helicopter appears the train and prompts the mercs to board. The pilot's announcement of the first pickup (who was actually the porter) as well as the pilot's reaction to the fight between the porter and the female merc indicates that he expected to pick all of them up.
FleetCommand