Ms. Choksondik writes her name with her right hand, but the next word "Life," with her left. In the next scene, "Life" is gone.
Kenny appears in class after he dies, when the new time machine is activated.
When the nerds first start the argument about the number of star trek episodes there are, one says there are 72, the other says 73. For the remainder of the episode, they switch sides on the number of episodes.
In this episode, the two Star Trek nerds argue for almost the entire episode about how many episodes there were in the original Star Trek (1966) series. One says 72; the other, 73. They both got it wrong. There were 79 episodes in the original Star Trek series.