In the opening scene, one of the callers into the 911 centre states "I think I'm having an overdose and so is my wife" - the line made famous by Edward Sanchez, a policeman who confiscated marijuana from a suspect and then made brownies with it. He called 911 when he thought he had taken too much.
Halle Berry was initially cast in the lead role with Joel Schumacher directing. Schumacher dropped out and was replaced by Brad Anderson. Berry dropped out due to scheduling conflicts but once the start date was pushed up, she returned in the lead role.
In the final fight scene where Jordan is thrown to the ground Halle Berry hit her head on the concrete. The on site medics said she she only had a bruise and a bump on her head and was okay to continue filming, but noted she could have suffered a brain injury if she landed differently.
When Jordan is talking to Michael Foster on the cell phone for the last time, there is no sound of metal clanging. But later when she listens to the recording of the call, the metal clanging sound is heard.
When the kidnapper is holding the screwdriver to Casey's face and threatening her, the screwdriver moves from beside her ear, to in front of her nose, to back beside her ear between shots.
When the first eyewitness calls from the freeway, she states the model of the car. During his dispatch, Marco also states the model of the car. As time passes, Casey pours paint out of the broken taillight while Jordan dispatches to police. But she states the car as unknown make and model. This information would've been relayed to her.
What are the differences between the US Version and the German Version?
A
The German version and the US version differ right at the end, which doesn't change the ending itself; it rather adds a minor thing without major consequences. The additional scene can also be found in the bonus features of the US Blu-ray, just with slightly different shots than in the German version. The same alternative "alternative ending" is also included in the bonus features of the German version again. A detailed comparison between both versions with pictures can be found here.