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.
Answer: Bob Denver answered this when he was on a talk show hosted by Pat Sajak. He said they were going to write into an episode where the castaways found all these clothes, but it got too complicated, so he said, they decided, "who cares, it's only a TV show," and forgot about it. So the writers and actors even asked this, they just never bothered to address it.