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)
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.
Factual error: The Woman talking with Mamie and Emily about the jams is wearing 1970s large framed glasses. (00:33:15)
Other mistake: Maryellen wears visible eyeliner throughout the show, despite being during the depression. She wouldn't be wearing any makeup.
Suggested correction: Why wouldn't she be wearing makeup during the depression? Especially if it was just a small amount. This isn't a mistake, just your opinion. Women continued to wear makeup during the depression, and not just starlets or the rich and famous. In fact, makeup sales overall hardly took a dip during the depression because women through the US were still buying it.
Despite that women did wear it during the Depression, part of the factor being that the Waltons wouldn't afford such a luxury, considering their very tight pockets. Otherwise, we'd see Olivia preening herself also, before she goes anywhere. But doesn't even wear lipstick. And Maryellen is never 'caught' actually putting on the eye makeup. So it's likely not any opinion.
