The bottle of ether that's caused to fall on its side is upright in the next scene.
In The Trap (1968), the castaways used a cart fashioned from a giant sardine can and four soda pop bottle caps. Barry even rides in it. However, in this one, they mention having to use a stretcher to carry him to the place where they would meet Dr. Brule to perform the appendectomy. They should have used the cart.
Not a continuity error because an unknown amount of time would have passed between the two episodes for some off screen possibilities. In theory the cart could have fallen apart, was abandoned, or recycled for other uses. It is also possible that the path they take to meet the doctor is too lumpy for the cart. Captain Burton could have radioed to the others, telling them that Barry should be brought over by stretcher for security reasons (For example: It is quicker to carry Barry by stretcher than by cart, should they need to make an escape).
Not a continuity error because an unknown amount of time would have passed between the two episodes for some off screen possibilities. In theory the cart could have fallen apart, was abandoned, or recycled for other uses. It is also possible that the path they take to meet the doctor is too lumpy for the cart. Captain Burton could have radioed to the others, telling them that Barry should be brought over by stretcher for security reasons (For example: It is quicker to carry Barry by stretcher than by cart, should they need to make an escape).