Visible crew/equipment: When Tom is ringing the pager number from the phone box, you can see office workers watching the filming of the scene from an upstairs window.
Character mistake: The voice tells Tom that the alarm deactivation code is 47223. However, when Tom enters the code subsequently to deactivate the alarm, he only enters "4723." You can tell he doesn't enter a fifth digit because the keypad chimes each time a digit is entered.
