Deliberate mistake: When the two girls have get into the limo for the first time with the fake Chinese guy and they realized that they are now trapped and being taken away, there is a shot of one of the girls through the limo's window, limo windows aren't clear they are tinted so we shouldn't have been able to see her face.Disney-Freak
Continuity mistake: When Roxy fights the fake Chinese guy with her drumsticks in the subway station, Jane and Roxy end the fight by grabbing his coat/jacket and pulling it over his head, then shoving him into a subway car. When they first shove him, the jacket is over his head. When he is stumbling in, it is suddenly nice and neat, down in its proper position. But the in the next shot of him hitting the seats, it's back over his head as he struggles with it.
Continuity mistake: Roxy's hair's waviness varies throughout the entire movie until it is finally completely straightened when she comes out of the House of Bling.
Factual error: When the band (Simple Plan) is playing, the name "Lomax" is repeated by many people, including Simple Plan's drummer (Chuck Comeau), however, while playing the drum set, it is hard to pay attention to almost anything besides what you are doing without messing up on the song.
Continuity mistake: In the scene right after Jane and Roxy escape from Lomax and they are still in the taxi talking to each other. Roxy's hair goes from tucked behind her ears to in front of her ears between shots.
Continuity mistake: When the fake Chinese guy calls Jane on her mobile in the hotel room she calls for Roxy. If you then look at Roxy's hair you'll see its position change several times. First over her ear, then behind her ear then, over her ear, etc.
Revealing mistake: Just before Jane knocks over the coffee into the guy on the train, you can see that she looks at it before she hits it, so that she knows where to hit it.