Is There a Doctor in the House? - S1-E13
Other mistake: At the end of the episode, when they were looking at the chart they created, and Alice was found to add the measles, you see Mike Brady adding the word "Alice." But the kids and Tiger all had columns, but he is adding her as an extra row, which was for the different illnesses, to suggest that Alice was an illness instead of a person having the illness.
Continuity mistake: The home number Mike dials in the men's bathroom to check on the kids, is very different than the home number Carol dials in the ladies restroom. (00:18:30 - 00:18:56)
Visible crew/equipment: A shadow of a boom mic is visible moving across the brick wall just as Alice starts to punch Mike in the stomach.
Audio problem: When Peter is hinting to Carol that he is still growing, the audio changes to being dubbed in from Peter separate from the actual scene after Peter stands up and mentions he wants cowboy boots. Then the audio is back to normal once Peter mentions "Brown" cowboy boots.
Continuity mistake: The kids walk into the kitchen complaining about the noise from Jan's tap dancing. Peter reaches up and grabs his paper sack lunch and then in the next shot he says "talk about noise pollution" while grabbing his lunch for a second time. (00:09:07)
To Move or Not to Move - S1-E23
Visible crew/equipment: When Alice and some of the kids are in the den Bobby gets up to turn off the TV, and the shadow of the moving boom mic is visible on the wall behind Peter. (00:14:05)
Continuity mistake: When Mike walks into the kitchen asking Alice if he can give her a hand, Alice removes two pots from the stovetop leaving the left side clear, but in the shots from the dining room when Alice trips, there are two large pots on the left side of the stovetop, near the edge of the counter. (00:01:20)
The Grass is Always Greener - S1-E24
Visible crew/equipment: When Mike returns home with the grocery bags, as he sets them on the table Alice walks over, and the shadow of the moving boom mic is visible on the swing door behind Mike, at the top left side of the screen. (00:11:05)
Visible crew/equipment: While Mike is fiddling with his golf bag the morning after Tiger disappeared, just as Mike tells Bobby there's nothing to worry about because his siblings are checking the neighborhood, the moving shadow of the boom mic is visible in the top right corner of the screen. (00:02:45)
Continuity mistake: In a first-season episode, Carol is asked by one of her daughters, "How come you never play golf anymore?" indicating she used to play golf. In the later seasons, an episode came out where Carol was first learning to play golf (appearing as if she's never played before).
Dough Re Mi - S3-E16
Plot hole: Greg bought a time spot in the music studio to record a song. He writes a sudden new song for the studio at the last minute and then, next scene, the kids are singing the song in the studio along with background music playing. Where did all the instruments come from and who was playing them? Even if pre-recorded, Greg and the other kids would have just shown up at the studio at their time, and no way they would have been able to get the tracks down in advance to an unknown song like that.
Fright Night - S4-E6
Plot hole: After the girls get their revenge on the boys in the attic, they explain the mysterious "I must have air" voice from the trunk as it's revealed to be from a tape recorder. Marcia mentions a set up the girls had where they played the tape recording (from their bedroom) when they were ready. This is impossible as the recorder was in the attic trunk and the play button would have had to be manually pushed down by an actual person to activate.
Character mistake: At the end of the episode when all the kids line up to head upstairs, Mike gives instructions to line up according to their size (big to small). If you notice carefully when the kids all line up, Peter stands behind Marcia, yet he is slightly taller than her.
Continuity mistake: At home, before leaving for the Grand Canyon, the trailer was much taller than the car, and looked more like a motor home. After that, it becomes a different vehicle more like a trailer, about the same height as the car. When the prosecutor steals the car, it's the tall version, and when they arrive at the Grand Canyon to look at the view, there's nothing attached to the car bumper. When they leave the Grand Canyon it's the shorter version, back to being a trailer.
The Dropout - S2-E1
Other mistake: When Greg is in the kitchen getting ready to leave for the baseball game, there is a number 53 on the back of his jersey. In the following scene at the baseball park, there is another man with his back turned throwing practice balls, who also has the number 53 on the back of his jersey. It is clear that it is not the same person.
The Dropout - S2-E1
Character mistake: When Greg was in his room talking to his parents, he said that Joe DiMaggio, Mickey Mantle and Yogi Berra never went to college. Joe DiMaggio attended Yale University, Mickey Mantle attended the University of Oklahoma and Yogi Berra attended Montclair State University.
Suggested correction: DiMaggio dropped out of high school and worked odd jobs before playing semi-pro ball. His son, Joe DiMaggio Jr attended Yale for one year. Mantle was offered a scholarship to Oklahoma to play football, but he never went. He started playing semi-pro ball at the age of 17. Berra dropped out of school after the 8th grade and then signed with the Yankees when he was 18 (but served in the military before playing). Montclair State University gave Berra an honorary degree in 1996.
The Voice of Christmas - S1-E12
Revealing mistake: Carol's hair is quite noticeably shorter in an almost 'Twiggy' bob. When in the prior episode 'Vote for Brady' it was past her shoulders, curled into a very fashionable bubble flip. Not that she wouldn't have visited the stylist after the campaign. Just a very noticeable difference.
Suggested correction: The episodes were aired out of order, so this episode did not immediately follow the previous episode in production. Plus, this was a Christmas episode and Carol was preparing to sing in the holiday service, which is just one possible reason why she'd change her hairstyle.