When walking up to the Waltons' porch, Merie Earle, playing Maude Gormley, flubs her line and says, "I came to visit with Bertha" instead of Myrtle. She can be seen rolling her eyes and looking upward in an exasperated state, but the actors continued on with the scene anyway.
At the restaurant, when Stella asks Olivia to tell her about the rest of the Walton family, Olivia is heard starting her next sentence with: "Oh...", but her mouth clearly forms the word: "Well..."
In the opening scene, the shadow of the camera crane is clearly visible.