Factual error: The Literary Digest Sheriff Epp is reading in Godsey's store is dated Aug 1936, when only a year has passed since the show's inception at 1932.
Revealing mistake: When Maryellen runs into John-Boy's arms (after running away) Richard Thomas (John-Boy) breaks character as he looks into Judy's (Maryellen) eyes, by swallowing hard. Like a guy would do, when he's close to an attractive girl. Then later covers his groin with the cast, when John and the kids check up on him. The two young actors playing Jon-boy and Maryellen crushed on each other behind the scenes.
The Carnival - S1-E3
Revealing mistake: When Jonboy, Jason, Ben, and Elizabeth are trying to lure the monkey down from the tree, the leash it's tethered to is visible down the tree trunk. But then disappears after the monkey climbs down.
The Carnival - S1-E3
Visible crew/equipment: Near the end, when the clowns are performing their act for the Waltons, the monkey's leash is visible as it makes it way across the tightrope, before jumping down.
Factual error: When John-Boy and Jason walk into the theater, there's a poster for the movie Breakthrough, released in 1950, which is about the Battle of Normandy that didn't even happen until Summer 1942. This episode was set in early 1934. (00:50:55)
Revealing mistake: When John Boy and the others are watching the movie being shot, a helicopter can be heard. This takes place in 1936 with The Abdication of Edward VIII, and there would be no helicopters around at that time. (00:25:20)
Character mistake: When Rose introduces Elizabeth to Mr. Perkins she is introduced as her niece, when in fact they are cousins.
The Townie - S1-E24
Deliberate mistake: When Ted sees Ep's roadblock he turns the LaSalle Coupe around to avoid the sheriff, and the next wideshot of Ted and Sarah driving the LaSalle down the road is a flipped shot, note everything is backwards. (00:36:45)
Factual error: After the shot of Erin and Paul driving to his home, which is about half an hour up the road, when it cuts to the exterior shot of the Assayer's office building, all the vehicles parked outside are from decades later. (00:32:10)
Character mistake: When Rev. Andy visits Elizabeth at the bridge to talk, the buttons of his shirt are too far down, revealing his chest hairs, which would be most inappropriate for a minister.
Other mistake: John yells at the kids, "All right, everyone go to sleep now. It's getting late," when it's still daylight outside, possibly just after dinner time.
Other mistake: The Walton boys are in the military. None of them have military haircuts.
Other mistake: During almost any random episode of the family hanging out on the porch after dark, the moonlight is unusually bright, indicating obvious studio lights in their faces, or plug-in lamps on extension cords for actual light attached to the porch ceiling or whatnot.
The Spoilers - S3-E8
Other mistake: During the somewhat pointed discussion with the Hanover family at dinner, Olivia suddenly has the girls help clear the table when all their plates are still full, which wouldn't happen during a depression with money so tight.
Revealing mistake: Throughout most of the episode, The Car is a standard black with chrome trimming. But at the end it's suddenly beige when Johnboy and the kids are polishing it for their first ride.
Suggested correction: At the end it's not "suddenly beige." Mid-episode Mary Ellen mentions a family project to, "Design you a new-looking car" and Erin adds, "We can paint it." Soon John-Boy says, "I'd like to paint it a nice dignified shade of tan." In the penultimate scene John-Boy drives Hyder and Martha Rudge back home. Time passes offscreen. It cuts to the final scene with Mary Ellen and Erin placing their new cut/sewn seat covers in the newly painted tan car, and nobody is "polishing it for their first ride."
Factual error: Considering it is the Depression, it is highly unlikely that the family would have any electricity in The House. With maybe the exception of a lamp or two, as rural folk typically didn't have such accommodations in 1930. Yet every room has some form of fancy lighting display.
The Legend - S1-E11
Other mistake: During close-ups of the kids, Maryellen is the only one of the girls wearing very visible eyeliner and mascara, that weren't apparent in earlier episodes.
Other mistake: When Elizabeth's horse takes the bad fall, Maryellen tells them it has a broken hoof. So they put the horse down instead of taking it to a nearby vet for help.
Suggested correction: This episode takes place in 1945. We see Mary Ellen look toward the mare's front (not hind) legs/joints, which are weight bearing; and when Mary Ellen tells Elizabeth about her mare, Molly, Mary Ellen's actual words are, "Elizabeth, it's her leg. It's broken. It's bad. We're gonna have to put her out of her misery." Viewers are not shown what Molly's "bad" break is, but with Mary Ellen's words, we know the break is severe, which was a death sentence for any horse. Just to add, it all completely depends on the location of the equine injury and the severity of the break/fracture. Nowadays, with modern advancements in equine veterinary care, (thankfully!) some severe breaks may not be a death sentence for a horse.
Factual error: The Woman talking with Mamie and Emily about the jams is wearing 1970s large framed glasses. (00:33:15)
