During the scene where Roy and Chon are drunk in the hotel, director Tom Dey hoped to include a drunken kung fu scene as an homage to The Legend of Drunken Master (1994) (Legend of the Drunken Master (1994)). There was no time to choreograph such a scene, so Dey showed Chon blowing bubbles from his mouth, as Wong Fei-hung does in the Drunken Master movie.
Chon Wang is the Chinese translation/pronunciation of John Wayne. However, in the case of Jackie Chan's character, Chon represents his last name while Wang is his first name. This represents the order Chinese names are presented.
There is a brief scene where a pioneer couple watches from a distance while two of the Chinese railroad workers practice martial arts with large knives. The woman comments that "they don't look like injuns", and her husband replies that "they're not injuns, they're Jews!". This may be a reference to the doctrine of the Church of Jesus Christ of Latter Day Saints (Mormons) that the Native American peoples are actually the descendants of a lost tribe of Israel.
The song playing during the first bar-fight sequence ("La Grange" by ZZ Top) is the same song that plays during the The Dirty Dozen (1967)-style intro of the characters in Armageddon (1998), an earlier Owen Wilson film.