Revealing mistake: In the closing scene, you can see the modern curb & sidewalk have been covered with dirt.
The Shootist (1976)
1 revealing mistake - chronological order
Directed by: Don Siegel
Starring: John Wayne, Ron Howard, James Stewart, Lauren Bacall
Continuity mistake: A couple of times in the movie, the camera pans to John Wayne, and his hair is parted on the wrong side. (Reverse editing flaw).
Carson City Marshal Walter Thibido: The day they lay you away, what I'll do on your grave won't pass for flowers.