A sign is up on the Wilder's front door that says, "Small Pox Keep Out." It is there when Doc informs Isaiah that Rose has smallpox, when Isiah delivers supplies, when Doc comes in from the barn, but it is gone when Almanzo leaves the house to go tell Doc in the barn that Rose's fever has broken. After Rose's recovery, the sign reappears on the door when Doc exits the house to go weep.
At the beginning of the episode, Laura states that it was lat summer 1889. In " Times are Changing Pt 1", Laura says that it's 1887. Rose should have been 2 years older, but had not aged.
At the 43 min mark Laura's fake wraparound braid is a different color than the rest of her hair.
When the townspeople address Dr. Baker at the stagecoach, the shadow of a piece of filming equipment moves around on Harriet's forehead.
Wild horses would not have kept Caroline Ingalls from the birth of another grandchild, especially since her supposed location of Burr Oak Iowa is only 400 miles from Minnesota.
Harriet would not have called Dr Baker a quack. He's the one who saved her from dying of a burst appendix in season one.