Liam Neeson performs many of his own stunts.
The map that Bryan is holding, when he finds out about the girls’ plans at the airport at the beginning of the movie, is an old Europe map (probably dated 1992), as the now dissolved Czechoslovakia and Yugoslavia can clearly be seen. Czechoslovakia separated into two independent countries, Czech Republic and Slovak Republic, in 1993. Yugoslavia was dissolved in 1992.
Maggie Grace was reportedly trained by world renowned running coach Alberto Salazar, in order to learn the finer points of running like a 12-year-old girl.
Just before the kidnappers take Kim, she yells out: “Beard. Six feet. Tattoo right hand, moon and star.”