Revealing mistake: When Eva is leaving with her suitcase, you can tell by the way she is holding the suitcase that she is ready to open it when it hits Magaldi.
Revealing mistake: When they attach a GPS device to the gang's car and they watch their situation on the computer screen, you can see on the left top part of the screen some playback, stop, rewind, . buttons, showing that it's a pre-made video that they play manually.
Revealing mistake: When "Roy" pushes Martin into the wall during their first meeting, you can see the wall shaking on impact. (01:14:30)
Revealing mistake: When the policeman is shot on the roof of the observatory and the police cars drive across the grass, you can see the tyre marks in the grass from previous takes.
Revealing mistake: When Kevin shows the Mayor the Times editorial about the judge he quotes a phrase from the article about whether the man would be a judge if not a former law partner of the mayor. Unlike many newspaper articles shown in films where if you read the article text it is actually jibberish, here it is a legitimate article criticizing the way judges are elected, but some parts are repeated, and it states nothing about the judge being a former law partner of the mayor.
Revealing mistake: After Seagal and the student jump off the window they land on the floor and for a brief but obvious moment one can notice it's not Seagal but his stunt double.
Revealing mistake: At the start of the montage in which Frollo ransacks Paris for the gypsy girl, the shot of the three soldiers kicking down the baker's door very briefly places the more distant soldier off to the right "in front" of the closer central soldier; this is a case of incorrect animation cel layering.
Revealing mistake: Looks like Frosty Cream is actually a Dairy Queen. When Karl is ordering, the menu board behind the employee lists items such as "DQ Sandwich", "Dilly Bar", and a spot where you see part of DQ's old motto.