This episode could be the one to answer the age-old question of why the castaways never built a raft to get off the island (or why the Professor wasn't smart enough to do so), as the raft that was built for Mr. Howell to get back to civilization immediately sank when he put out to sea.
The title comes from the question that the host of the TV game show "To Tell the Truth" (1956) asked the impostors to reveal to the panel and to the television audience who the real guest was and who the impostors were.
The castaways' radio is handled by 5 of the seven castaways, more than any other of this show. Only Ginger and MaryAnn do not touch it.
When preparing Mr. Howells raft, Mary Ann and Ginger come running up with supplies. Ginger hands the professor a small barrel of water which he immediately acts like it weighs 50 lbs, not empty like it really is.
As Mary Ann and Ginger are brainstorming in their hut, it's revealed that Mary Ann is left-handed. At first she's just holding a pencil in her left hand as they talk, then she's shown writing with her left hand.