Visible crew/equipment: While Andy's sitting on his desk going through the mail and Barney's sitting on the side desk, the actors' chalk marks are visible on the floor behind them, in the shots facing both of them.
If I Had a Quarter Million Dollars - S5-E22
Continuity mistake: After Barney makes his way around town spreading The Rumor that he has loads of money, when Barney walks into the courthouse he removes his jacket and hat then hangs them on the coat tree, and the hat keeps moving under and over the jacket between shots.
Continuity mistake: When Barney walks into the bank and turns on the light, we can see there's no damage to the side of the door, but when Andy walks in he points out the area where the door was jimmied.
Continuity mistake: When Barney's outside the bank loading his gun with the bullet, there are window blinds on the inside of the doors' windows - nothing else, but when Barney's inside the bank there are white shades between the glass panes and the blinds. As for the bank's large side window the opposite happens - there's a white shade between the pane of glass and blinds in the exterior shot, but in the interior shots we can see through the blinds' slats and there's no shade.
Other mistake: When Andy and Helen are in the squad car alone after going to the movies with Gloria, both car doors are closed, but in the closeups from outside both sides of the car, note that both triangular vent windows are missing and we can see the doors' rubber seal - both doors are open for these closeups.
Visible crew/equipment: When Gloria and Frank drive off at the end, just as the camera zooms in on Andy and Helen, the shadow of the moving boom mic is visible at the top, left side of the screen.
The Case of the Punch in the Nose - S5-E25
Other mistake: In the shots from outside the courthouse, when the front door is opened there's a wall where none should be, presumably to prevent seeing inside the courthouse facade.
Other mistake: After the preacher walks past Andy and Sam, when the two men comment that the preacher's sermons "go on" and are "dry as dust," we can tell that all of the store's glass window panes have been removed, presumably to avoid the crew/camera's reflections as the shot pans across the window to Howie.
The Arrest of the Fun Girls - S5-E28
Other mistake: When Andy, Helen, and Thelma Lou are parked in front of the courthouse the lights turn on, and in the closeups from outside both sides of the car, note that both triangular vent windows are missing - the two doors are actually open for these closeups. This happens again later, when Andy and Barney are each apologizing individually to Helen and Thelma Lou.
Aunt Bee's Invisible Beau - S5-E27
Other mistake: After Andy talks to the butter and egg man in Mt. Pilot, when Andy gets in the squad car with Barney all the car doors are closed, but in the closeups from outside both sides of the car, note that both triangular vent windows are missing - the two doors are actually open for these closeups.
Opie Flunks Arithmetic - S5-E30
Other mistake: When Aunt Bee walks out of the grocery/meat store the door's located between the grocery's one display window and the TV display window, but the grocery store actually has two display windows with its door between the two. This was shot on the soundstage, not backlot.
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.
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: 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.
The Arrest of the Fun Girls - S5-E28
Character mistake: Barney states when the Fun Girls were in town before, in Season 4, Thelma Lou didn't speak to him for 10 days. That's not true, they made up the same day.
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.
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.