Character mistake: After learning by telephone that he would be part of the Monkees and making records and a TV series, Mike says, "Man, it's a win-win situation." That expression was not in use in 1965; it didn't become widely used until the early 1980s.
Character mistake: In the "Casey At The Bat" sequence, the narrator says "The score is 4 to 2 with but an inning left to play." However, the scoreboard shows that eight and a half innings have been played, and only a half-inning remains.
Character mistake: Gail reads right through Katie's poor excuse about crotcheting, and says she won't go to the ball "after what you pulled today with Guy." She did not do it (well she didn't do anything, but 'supposedly did') today, but yesterday. (00:31:00)