When Freddie comes to Carly's apartment to borrow a tennis racket, Freddie leaves the door open. And when Spencer turns around to the kids about the Pak-Rat game, the door is shut. And when the close-up shot is on Carly and Freddie, The door is back open.
At the end of the show, Spencer wakes up and finds Carly asleep on the Pak-Rat machine. She asks him to carry her upstairs. When Spencer walks up to Carly, he is barefoot. The scene quickly cuts to Carly then back to Spencer, who is now wearing slippers.
After the commercial on the Sunday morning Spencer is crummy from being up all night. On the first close up of Carly and Spencer, Spencer's bangs are down and in front. In the next close up, his hair is more upwards. Also, Spencer's outer shirt is completely dry after being squirted by Carly.
At one point Spencer is playing Pak-Rat. The point of the game seems to be to eat the dots on the screen (a la Pac-Man). However, a closeup of the screen shows his character moving around in circles in an empty part of the screen, while Spencer talks about how good he is doing.