In the flashback sequences culled from the pilot TV movie "The Homecoming: A Christmas Story," the shots with Olivia and John Walton had to be redone since their roles were played by different actors in the movie. The house also looked markedly different in the pilot, so when the reshot scenes were edited together with the shots of John-Boy from the pilot, it looks like they're in two different houses.
In the flashback scenes, taken from the pilot TV movie "The Homecoming: A Christmas Story," John-Boy's hair is red, which it never was throughout the entire run of the series (for the pilot, all the actors playing the Walton kids dyed their hair red. For the series, they kept their natural hair color).
The exact same stock footage clip of New York City, showing the view down Wall Street towards Trinity Church, is used twice.
Flashback shows John Boy (Homecoming) very young telling Olivia how he feels about being a writer. Olivia (Michael Learned) looks much older than the first season as she wasn't in The Homecoming. They should have made her look younger if possible.