Revealing mistakes: When the girls are in the apartment in France, they turn the music up loud so they do not hear Kim's mobile phone ringing. When the camera pans over to her handbag, you can clearly hear the phone ringing, however the phone shows the "Silent" mode is selected.
Continuity: When Brian is interrogating Marko he removes his tie and loosens his collar. When he returns to the light switch his tie has returned, only for it to be missing again on his next trip to the light switch.
Continuity: When Kim is struggling with her abductors in the apartment, the area of the mirror that was broken changes between her smashing in to it, and Bryan going to the apartment to re-enact the abduction in his mind.
Continuity: In the Paris apartment when Bryan is re-listening to the recorded phone conversation, Kim is heard to say the line, "They took her." Earlier in the film Bryan doesn't begin to record the conversation until after this line is said. This line should not be part of the recorded conversation.
Factual errors: When Brian is talking to the kidnapper on the cellphone, the kidnapper hangs up, making the noise of a normal phone being put on the hook even though he was on a cellphone.