The Hunter - S3-E18
Continuity mistake: When Mrs. Howell talks to Ramu, he holds the spear waist high, and beside Lovey. After her question, the spear is suddenly chest high, and aimed about the top of her chest.
Gilligan's Personal Magnetism - S3-E21
Continuity mistake: When Gilligan knocks the door off the hut it lands on the Skipper's neck with the life preserver on the top. In the next shot the preserver is on the bottom.
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.