Dear Libby - S1-E2
Visible crew/equipment: When Carol questions Greg, Jan, and Peter about the argument she heard, Greg tells her it was on TV, and as the three kids sit down the actor's two tapes marks are visible on the floor in front of Peter's feet. (00:10:00)
Alice Doesn't Live Here Anymore - S1-E4
Visible crew/equipment: While "operation Alice" is underway, after Carol tells Alice to stop organizing the canned goods, when Alice places the step stool chair against the wall the black tape mark is visible on the floor where Carol had been standing, and then it's gone as the scene continues. (00:19:00)
Kitty Karry-All is Missing - S1-E7
Visible crew/equipment: After Bobby walks out of the family room playing his kazoo, when Cindy places Kitty Karry-All on the couch so she can get the bottle, the actor's black tape mark is visible on the floor beside the couch, where Bobby had been standing. (00:02:40)
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)

Visible crew/equipment: When Mike and Bobby drive up in the station wagon, just as Mike stops the car, on the left side of the screen we can see the edge of the house set. Instead of the usual wood fence in the yard, there appears to be a directors chair (provided to all cast members) in the dark background. (00:05:35)
Visible crew/equipment: After Alice trips on the Chinese checkers, when Mike gathers the kids in the family room to update them, the shadow of the moving boom mic is visible at the top right corner of the screen. (00:02:50)

Visible crew/equipment: In the episode where Alice sprains her ankle, Sam comes over and gives Alice some flowers. He leaves and Mike walks in, and the camera zooms into Alice and you can see two shadows of the boom mic, one on Mike's face and another over Alice. (00:14:00)
Visible crew/equipment: While Alice is hemming up Marcia's party dress, when Bobby and Jan walk into the family room the actor's black tape mark is visible on the floor in front of Bobby's feet. Note that it wasn't on the floor at the start of the scene. (00:10:35)
Visible crew/equipment: When the shelf falls in the store, you can see the rope attached to the top of the shelving unit being pulled from off-screen triggering the collapse of the shelving unit, it was not the girl's weight that made it tip.
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)
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)
Answer: I think I remember that episode - but, more importantly, my mother always told me (and my siblings) to stop jumping/ stomping, running in the kitchen, and opening the oven door when a cake was baking... because these could make the cake fall. I believed my mother... and I, as a child, also caused a few "fallen cakes" because I didn't quite always listen (right away, anyway). I'm sure Alice's fallen cake episode was exaggerated, but cakes really CAN fall from stomps and opening the oven door too soon. Usually, it has something to do with the baking powder and how the air bubbles change during the baking process. Doing something that might cause the oven and cake inside to move/shake can suddenly change the air bubbles inside the cake and cause a collapse. I don't know all factors that have to occur for a cake to fall (collapse in the middle), but I've seen fallen cakes during my adulthood and... well... caused at least a few myself. Regarding Alice's cake falling each time one of the Brady kids stomped upstairs, I'm not sure if a series of falls could occur. IF it is possible, I think there would have to be way too much baking powder in the batter or some other inaccurate combination of ingredients that alter the chemical process during baking.
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