After Isaiah shares lunch with Charles, the scene shifts to Nellie's Restaurant. The windows of the restaurant say "Nellie's Restaurant," however, the name of the restaurant was renamed "Caroline's" back in season 6. Later on, Isaiah is shown outside the restaurant and the windows now say "Caroline's Restaurant."
When Isaiah is reading the letter from Grace, her voice-over doesn't match all of what's in the letter.
During the scene involving Mr. Edwards fighting in the saloon, when he is punched and falls against the side wall, the wall is pushed outward, showing that this is clearly a set.
When Mr. Edwards first shows up in Walnut Grove, he goes to the mill to meet Charles and Almanzo. A jet contrail is clearly visible in the sky in the background.
The white feathery plants seen at 8:46 are pampas grass native to California and the Mojave Desert. They do not grow in Minnesota.
During the final baptism scene, Carrie (portrayed by Lindsay Greenbush) darts her eyes directly at the camera.