Other mistake: When Lucy and Ethel are on the back porch fighting about the washing machine and also when Mrs. Trumble walks out, Lucy's back door is open and we can see the shutters between the kitchen and living room, with the kitchen counter/sink underneath, but the sink's faucet which should be seen has vanished. (00:14:45)Super Grover
Other mistake: When Ricky and Fred hold up the newspapers with the big holes in the back page, we see the front page with the headline "Bond Issue Defeated", and it should look familiar since it's the same front page that was used in the episode "Ricky's Old Girlfriend", with the article about Carlotta Romero. (00:18:15)Super Grover
Other mistake: When Ricky puts the baby in the crib and begins telling him the bedtime story, in the closeups Little Ricky's sitting up beside the crib rails (at Ricky's side of the room), but in all the wideshots when the camera pulls back to show Ricky's lively storytelling, we can see that Little Ricky is not where he should be.Super Grover
Other mistake: The Ricardos and Mertzes are trapped inside an abandoned cabin after it is buried by an an avalanche. They are rescued by an oom-pah band playing "La Cucaracha." When the band members enter the cabin, their clothes and shoes are completely dry, and they don't track in any snow or water. Then when the Ricardos and Mertzes follow them out of the cabin, they leave their backpacks behind.
Other mistake: Lucy walks out on the balcony and sees Van Johnson sleeping on a lounge chair by the swimming pool. The photographic backdrop shows automobiles, trees, mountains, the Roosevelt hotel and many other buildings of Hollywood but when Lucy goes to the pool and sits on the lounge chair next to Van Johnson, the background is just a plain painted backdrop with no cars, trees, mountains or buildings. This plain backdrop also appears in the episode with Harpo Marx.Steven Lee
Other mistake: When the Ricardos and Mertzes arrive the first time at One Oak Cabins and Cafe the full moon is amid the tops of the trees. When they arrive the second time the full moon is in exactly the same location amid the tree tops as the first time they arrived. Fortunately, hours later when they make their sneaky escape from the cabin and return to their car the moon is no longer in view.