Continuity mistake: When Opie and Arnold rush into the house and tell Andy and Aunt Bee about the party, in the shots facing the boys we can see the reflection in the mirror behind them, and there's a lamp atop the credenza, but in the shots facing Andy and Aunt Bee that lamp doesn't exist.
Opie Steps Up in Class - S8-E5
Continuity mistake: When Aunt Bee picks up Opie at Billy's house, she parks the car in front and walks up to the front door. In the wideshot there's a space of approximately 3-4 feet between the blue window shutter and the door trim under the pediment, but in Aunt Bee's closeup there is no space whatsoever.
Opie Steps Up in Class - S8-E5
Continuity mistake: When Aunt Bee drives up to the Hollander house with Opie, in the wideshot the car's rearview mirror is affixed to the windshield, but in the closeup the mirror has vanished.
Continuity mistake: At the end, when Aunt Bee serves dessert her spoon and napkin are on the table, but in the next closeup of just Andy and Opie her spoon and napkin have vanished, then when Bee's seated she removes her napkin and her own dessert and spoon should still be on the table, but in the closeups of Andy and Opie they're not.
Opie's Group - S8-E9
Continuity mistake: While the Taylors are having dinner and talking about Opie's band, Opie has a filled dinner plate, salad plate, glass of milk, and flatware spread out on the table in front of him, but it all disappears in the shots facing Aunt Bee and Andy.
Barney Hosts a Summit Meeting - S8-E21
Continuity mistake: In the scene where the meeting participants are in the kitchen, the Russian guy opens the icebox, does not close it, and sits at the table. When Aunt Bee comes in immediately thereafter, the door is closed. She opens it again and partially closes it; but in the next shot, it is fully open.
Suggested correction: The first part of the mistake is correct. However, after Aunt Bee partially closes it, if you keep your eyes on the left side of the screen where the ice box is and watch carefully, you can see the ice box actually bounces back open fully on its own.
Aunt Bee's Big Moment - S8-E23
Continuity mistake: When Opie asks his father how to spell the word "Renaissance," Aunt Bee holds a plate of assorted cookies, but when she stands up and heads to the kitchen the type of cookies on her plate have changed.
Continuity mistake: When Andy finds the old newspaper clipping in Helen's box he tucks it into his pocket, but when he's looking at the clipping while he's at the office the newsprint on the back is entirely different. Then when Howard reads it the newsprint changes yet again.