When Kate goes on-line to lure the traffickers, she says that she has no college degree and that she is a kindergarten teacher. This is self-contradictory as virtually all teachers, from kindergarten through high school, are required to have a college degree for employment.
When Katya (Kate's Mail Order bride account) receives the first email from "Jeff" the subject is "Re: Hi Katya" even though it is the first contact from him. She then responds and when he writes back replying to her email the subject line of this second email is simply "Hi Katya".
In what is supposed to be Washington, they show a train with the symbol for AMT (Agence Métropolitaine de Montréal), a suburban rail network connecting the greater Montreal metro area (the 450 area code) with Montreal, which proves that this scene was filmed in the Montreal area (not Washington).
When the ICE officer in disguise checks in at the airport you can clearly see on the monitor of the customs officer that it is written Chisinau. Chisinau is the capital of Moldavia, a country near Russia, when in fact it is said that she comes from Moscow, Russia having demanded a Russian email address.
When Kate checks in at the airport and her passport is scanned, it shows up on the monitor her name, place of birth and eye color "albastri", which means "blue" in Romanian/Moldavian. Kate has brown eyes.
Russian Kate Morozov's surname should be 'Morozova' - note the feminine affix 'a'. Although the surnames of Slavic descendants in English-speaking countries have proper gender forms ignored or dropped (mostly for practical reasons), the character Kate was born and raised in Russia and so her surname would follow Russian suit.
When her passport is scanned at the airport, the text of her surname on the monitor readout is clearly a different font than the rest of the text on the monitor. This combined with the data/age discrepancy indicates they took a real readout of someone and used it with only changing the surname.
The "Destination Airlines" billboard has a Corbis "watermark." The image used for the special effect is from the Corbis stock photography service. "Watermark-free" images are available to the photo service's subscribers.
The goof item below may give away important plot points.
When Kate registered on the online dating site posing as a mail order bride, she lists her age as 21, even though she looks older. When her passport and visa are scanned at the airport, her birth date is listed on the monitor readout as 7/9/1988. A few seconds later as her passport is stamped, the date on the stamp reads 6/28/2005. This would make Kate only 16 years old, two weeks shy of her 17th birthday. As the traffickers examine all girls' papers, this would have stuck out like a sore thumb and made Kate very suspect.