Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Harold the Butcher: In some shots of Mr. Green's meat store, its front door handle switches to the opposite side. Such as at the start, when Harold stops in front of Mr. Green's meat store because he's hungry. Also, while Harold sits across the street from the meat store, Green asks Arnold if Harold is still out there, and the store's front door handle is on the wrong side of the door. Next shot, as Arnold exits the store, the door opens properly. (00:19:30)
Helga Blabs It All / Harold the Butcher - S3-E1
Other mistake: In the credits, actor Elliott Gould's name is misspelled as "Elliot Gould." (00:22:55)
Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Helga Blabs It All: When the boys get ice cream from the Jolly Olly ice cream truck, Arnold gets a chocolate popsicle, and Gerald gets an ice cream cone. Then, when Helga falls into Arnold's attic bedroom, all the boys stare at her, and as Helga backs out of the room, the ice cream cone Gerald holds changes to a chocolate popsicle.
Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Helga Blabs It All: While Helga hides in the overhead ventilation shaft, the vent cover has either four, five, or six slat openings in various shots.
Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Harold the Butcher: The front door of Mr. Green's meat store has either "Green Meats" or "Green's Meats" printed on the door's window.
Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Harold the Butcher: Mr. Green's meat store has a shopkeeper bell over its front door that vanishes in some shots, then it reappears. For instance, the bell is gone when Arnold is in the store while Harold sits across the street, but we hear it jingle and then the bell reappears when Harold enters the store.
Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Harold the Butcher: At Mr. Green's meat store, there are at least two instances that the word "MEATS" is misspelled as "MAETS" on the store's aprons. When Mr. Green gives Arnold the package for Grandma, Green's apron changes to the misspelling. Then, when Harold returns to help Green with the crowd of customers, Harold's apron has the misspelling.
Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Helga Blabs It All: While Helga is in the ventilation shaft, when she calls Phoebe for help, the rope is tied around Helga's waist with a knot at the front, but it cuts to a closer shot and the knot vanishes.
Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Helga Blabs It All: After Helga successfully snatches the message tape, when she rushes out of Sunset Arms the front door is missing its handles, but one handle reappears when Campfire Lass and other girls chase after Helga.
Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Helga Blabs It All: Phoebe stops the Jolly Olly ice cream truck and gets inside. As they head toward Arnold's house, in the interior shot a rearview mirror appears on the windshield where there wasn't one. Then, when the ice cream truck is parked in front of Sunset Arms, there are some changes to its appearance.
Helga Blabs It All / Harold the Butcher - S3-E1
Continuity mistake: Helga Blabs It All: While Helga goes after the tape at Sunset Arms, room numbers repeatedly change/vanish, or doors disappear and reappear. Some examples: Door 3 vanishes when Helga lowers herself via rope the first time. When Arnold unfolds the attic stairway, the closest doors are 7 and 8, but when Arnold and Gerald run down those stairs, door 8 changes to door 1. When Grandpa talks to Mr. Hyunh, door 1 is now door 3. When Grandpa and Ernie enter Hyunh's room, door 7 becomes door 5. When Grandma exits door 4, it then changes to door 2.
Casa Paradiso / Gerald's Tonsils - S3-E3
Other mistake: Gerald's doctor's name is spelled "Murray Stieglitz" on the sign, but "Steiglitz" in the credits.
Arnold's Room / Helga vs. Big Patty - S3-E4
Other mistake: Helga vs. Big Patty: When Helga dreams about boxing Patty, as she steps back from her, she is standing in mid-air for about a second. (00:17:00)
Arnold's Room / Helga vs. Big Patty - S3-E4
Continuity mistake: In the locker room, Sid's hair goes from stringy to full and back to stringy.
Curly Snaps / Pre-Teen Scream - S3-E6
Audio problem: Curly Snaps: At the start, Curly talks to Arnold about how good it is to be ball monitor. When Arnold says, "Well, I never thought of it that way," his mouth stops moving after the word "it." (00:01:25)
Curly Snaps / Pre-Teen Scream - S3-E6
Other mistake: Pre-Teen Scream: When the kids are sitting on Arnold's stoop in the beginning, there are two shots where Arnold's pants are the same colour as his skin, giving the sense that he has no pants on. (00:12:03)
Curly Snaps / Pre-Teen Scream - S3-E6
Audio problem: Pre-Teen Scream: When Phoebe turns on her CD player and reveals her Ronnie Matthews posters in her room, she says, "Now to compose the winning contest entry," but her mouth isn't moving at all. (00:13:00)
Curly Snaps / Pre-Teen Scream - S3-E6
Continuity mistake: Pre-Teen Scream: When Phoebe shows up at Helga's house to pick her up for the concert, Phoebe is wearing a red outfit with a red scrunchie in her hair. Thereafter, for the rest of the episode, her red scrunchie changes to her normal yellow one in some shots. (00:15:46)
Grandpa's Birthday / Road Trip - S3-E7
Audio problem: Road Trip: When Miriam points out the Wheeler Inn and Big Guy Restaurant while driving, as Helga says, "I really don't think," her mouth does not move. (00:14:56)
Grandpa's Birthday / Road Trip - S3-E7
Factual error: Road Trip: Whenever Miriam and Helga's car is on a broken white line road, the two lanes are moving in opposite directions; lanes on broken white line roads are supposed to move in the same direction. (00:17:15)
Answer: The show is based in present day times. Plus most cars aren't old fashtioned, I recall seeing a limo and not to mention a cherry picker, etc.