Continuity mistake: When the imposter Gilligan is playing chess with Mr. Howell, the long shots show the imposter holding the spoon transmitter near the center of the table the chess board is on, whereas the close-ups show the transmitter close to the edge of the table.
Continuity mistake: In the hut, "Gilligan" has the spoon of his transmitter knife open so his commander can hear the conversation. In the wide angle shots, the spoon is half way out. In the close ups, it's fully in position.
Chosen answer: It looks like a mistake to me I see it when the Professor is put into a trance, but it is not there later.
Bowling255 ★