Plot hole: When Mike was at the meeting and pulled out the Yogi Bear poster, he said he could find the other cylinder, and was told by one of the other men that they had to catch a plane in 30 minutes. After that, he had to find Jan, and then Jan and Marcia had time to go on about 4 rides and then find the sketches and then start their run across the park. There is no way all of that could have been done in less than 30 minutes.
Visible crew/equipment: When they're all practicing the Charleston, while Bobby's watching from the stairs, everyone is shown dancing from different angles, and in the low angle shots facing the kitchen the top of the kitchen set is visible, particularly when Carol twirls her necklace.
Audio problem: When the kids are painting a cardboard tree for the play, they ask their dad what he thinks of it. He then says "you better ask the two poodles next door." As he walks away he seems to almost trip/fall over something. Then the mom is heard laughing, even though she's not in the scene.
Revealing mistake: When Mike's boss, his wife and two other guests arrive at the house for a night of pool, the four guests are greeted at the front door, enter the brick entry foyer, and descend the steps into the living room. As the camera pans to capture the guests entering the living room, the obviously unfinished and unbricked end of the entry platform can be seen in the shot.
Continuity mistake: Near the beginning, Greg is painting the shutter green, he gets a phone call and goes inside. The paint bucket falls on Bobby because the ladder falls. Greg sticks his head out the window and asks who took his ladder. The shutter now has no paint on it.
Other mistake: When the boys are playing football in the backyard, watch Greg's right foot - at one point he slips on the Astroturf lawn, causing it to wrinkle and exposing a seam on the "grass" lawn. (00:03:20)
Plot hole: The Bradys and Alice run a relay through the amusement park to get the sketches to Mike at the manager's office. They locate another person to pass the cylinder off to when they get too tired to run. But they all arrive together seconds after Carol gives the sketches to Mike. (00:19:15)
Audio problem: Bobby is lining up a pool shot. There's a cut to Cindy, and as she says her line, the sound of pool balls being hit is heard. But when the pool table is shown again in the next shot, none of the balls have moved. Also the pool table moves from outside to inside. Lots of mistakes with the balls on the table throughout the game. (00:08:25)
Plot hole: Greg Brady is suppose to be under 21 so he can't legally sign any type of contract, also at the end he rejects his new persona and tears up the contract. Tearing up a contract doesn't nullify it.
Continuity mistake: During the goat in the master bedroom scene, the flowers on Carol's side of the bed change during the scene. At first there is a pink flower to the right of a white flower, and then it changes to white flower on right of the pink one. In addition, the whole bouquet looks slightly different in different shots.