Continuity mistake: As Mr. Howell tells his story, the table Ginger is on rocks to the point the canteen beside her falls off. A second later, she's drinking out of it.
Continuity mistake: While the castaways are standing around while their clothes dry, Mary Ann is not wearing any shoes. As the scene continues she is shown standing wearing black shoes. (00:05:00 - 00:06:00)
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.