Other mistake: Richard Benjamin kicks in the door to the hotel room to shoot Yul Brynner, a.k.a. the gunslinger. When the gunslinger falls backwards out of the window his black hat never falls off, it stays on the whole time.
Westworld (1973)
1 other mistake - chronological order
Directed by: Michael Crichton
Starring: James Brolin, Richard Benjamin, Yul Brynner, Norman Bartold
Continuity mistake: During the first gunfight between The Gunslinger (Yul Brynner) and Peter (Richard Benjamin), The Gunslinger is seen being shot in the middle of the body from the back. But, when you see him a second or two later, the shot is well over on his right side.
Arrivals Announcer: In trailer: Nothing can go wrong... go wrong... go wrong.
Trivia: Yul Brynner, whose Man In Black character was made famous in earlier American western movies, agreed to reprise the character in Westworld for only $75,000, because he sorely needed the money.