Factual error: Gabriel kills the engineer and sets the train to full speed, then locks the control room. Without the engine being resupplied with coal it would lose power and stop before too long, never getting as far as the bridge.
Suggested correction: It is known for firemen to fill the loco up to allow it to run for 15-20 minutes without new coal. However, it could not run that long at that speed without the boiler being refilled with water, so the boiler would have exploded well before the fire reduced.
Other mistake: Ethan (in disguise) throws some gas grenades in the office where the security heads are meeting - there's a massive explosion. Bright green gas fills the room... And everyone working on the typewriters in the room below completely ignores this, despite having a clear view into the glass window/wall of the office above. Even after a couple of minutes of Ethan and Kittridge talking, the phone rings with someone checking on them, rather than security busting in the door immediately.
Suggested correction: The three explosions aren't especially loud. The sound would likely easily be deadened by the walls and windows. The resulting powder (not gas) that's released is only present for a few seconds before dissipating. Since everyone in the typing pool is so focused on their work, it's quite possible it went unnoticed.
