Revealing mistake: At the end, in the shots of the kids dancing in class, the width of the wall between the shelf/coat hooks and the perpendicular wall with the door has bizarrely increased by 1-2 feet, but that extra width is gone in previous and following shots. Presumably they needed extra space for all the kids to dance so they moved that left wall.
Other mistake: In this episode (aired Sep. '64) Barney tells Andy that 5 years ago on May 16 (1959) he joined the sheriff's office, and later they all have a surprise party for Barney. However, in season 4 "Citizen's Arrest" (aired Dec. '63) Andy tells Barney that he found, "The custody receipt for the first revolver I issued you... August, 1953... 10 years ago last month since I swore you in." Andy even mentions having a party with a cake that has 10 candles on it.
Visible crew/equipment: While Ollie's making up excuses to rush home, he and Nora are saying goodbye to Aunt Bee, and the reflection of the moving boom pole and mic are visible on the car's windshield.
Continuity mistake: When Aunt Bee, Andy, Ollie, and Nora are in the kitchen for breakfast, the bag of flour vanishes from the counter depending on the angle of the shot.
The Education of Ernest T. Bass - S5-E4
Other mistake: After Ernest T. breaks Helen's window Andy shows up, and there's black tape adhered to the chrome trim at the side of the windshield and also the chrome trim beside the vent window.
The Education of Ernest T. Bass - S5-E4
Visible crew/equipment: When Ernest T. runs across the street to help Helen with her groceries she rushes away from him and heads up the block to Andy, and as Andy and Helen walk toward the courthouse the shadow of the boom mic passes across the white pillar in front of the door.
The Education of Ernest T. Bass - S5-E4
Continuity mistake: In Season 3, Mountain Wedding, Earnest T knows how to read and write. He writes a letter to Andy and uses a rock to throw it in. In The Education of Ernest T Bass, we are told that Ernest T cannot read nor write.
Continuity mistake: Barney tries showing Andy what the "part bloodhound" dog can do for The Manhunt so Barney blows a dog whistle, and in the closeups of the growling dog the rope that was tied to his collar is suddenly lying on the floor, but it's back on his collar in the following shot.
Revealing mistake: When Barney blows the dog whistle to call Blue from the back room, the dog comes running and knocks Barney on his back, and we can see a bit of the cushion that's under Barney's back - it's visible within the shadow under him.
Other mistake: When the escaped convict takes Barney hostage, they walk away from the lake and Barney drops the piece of paper with the convict's picture. Later, when Andy walks across the grass he finds Barney's cap and the paper lying on the grass, but the problem is that Andy needs to pull up at the center of the paper because it's pinned to ground, presumably so it wouldn't move or blow away for the shot.
Continuity mistake: When Barney, Thelma Lou, and Andy are driving to Andy's blind date they're all in the squad car. When they're parked in front of Helen's house in the closeup shots the light mounted on the roof has vanished, the glass windshield's gone, the car's interior differs, etc., and then it changes back. The roof is black, then white, as well.
Continuity mistake: After Andy convinces Barney to take off the uniform and wear his suit, when they pull up to the courthouse in the squad car the rear-view mirror is on properly, but in the shot facing the windshield the mirror has vanished, and then it reappears.
Goodbye Sheriff Taylor - S5-E10
Continuity mistake: While Barney's trying to instruct the new deputy candidates, when he throws a tomato to Otis it splatters on his shirt, and a few things keep changing depending on the angle of the shot - the amount of tomato goo increases/changes position; the suspender's sliding adjuster changes height; the deputy badge changes position.
The Pageant - S5-E11
Continuity mistake: While Andy and Opie are sitting on the couch, Andy's on the phone talking about having to tell Aunt Bee to drop out of the play, and there are two candlesticks with candles on the server behind Andy, but in Andy's closeups they're gone.
Continuity mistake: While the Darlings are at Andy's house the first time, on the hutch that's against the wall behind the sofa, there's a vase on the left side of the bottom shelf which vanishes and reappears.
Three Wishes for Opie - S5-E14
Other mistake: When Andy asks Floyd and Judd about who he's supposedly marrying it cuts to Helen walking down the street, and the grocery store has only one display window, when it should have two windows, and there's a brick wall adjacent to the window which shouldn't be there. (Shot at the soundstage not backlot).
Three Wishes for Opie - S5-E14
Revealing mistake: Barney, convinced he can foretell the future, is in the darkened jailhouse, seated between Goober and Floyd at a table. Goober strikes a match and lights a lamp which is directly in front of Barney. The immediate illumination obviously comes from a studio light because the men's shadows on the wall are to the far left of the men, instead of directly behind them.
Three Wishes for Opie - S5-E14
Other mistake: When Barney uses the gypsy lamp and cards in the back room, in the shots with Goober and then with Opie while they're standing in the doorway, the wall opposite them has a barred window, but in earlier episodes that wall has the door that leads outside to the side of the building.
Revealing mistake: While Barney's explaining to Andy his new interest in realty they both walk to the back room, and just as they pass through the doorway the camera tracks too far to the left, so we can see the edge of the set wall and the rest of the back wall is missing. (The following shot is from the direction of that missing wall).
Character mistake: Barney claims he would be losing $3478 on the real estate deal not going through. Considering the houses only were selling for that amount or less there is no way he was making that amount of money on 5% commission.
Suggested correction: I have no idea where you got the idea the houses were being sold for less than $4K. In the beginning Barney says Andy could get $24,000 for his house and $27,500 for the Williams' house (which is also how he got the figure that Andy can get into the Williams' house for $3,500, that's not the price of the house). Those 2 houses alone are $51,500 and 5% would be $2575, and he was losing out on 2 more houses.
That has bothered me forever! I thought the house Andy was thinking of buying was 3500 not 35000! Now the amount of commission makes sense although 35000 is LOT for a house in North Carolina in the early 60's! Thank you for clearing that up.
Just watched that episode and yes, you are correct on the math. But my problem is, new houses in this era were around $8000 - $8500 new, so these older houses would have been worth nowhere near $24-$27k.