Continuity mistake: In episode 11 of Season 4, it was stated that Leonard got an A in 1968, then opted for pass/fail to have the highest GPA in the college. In the final scene of this episode, however, it shows Greendale college as being established in 1974.
Continuity mistake: You can see the play director telling a pianist with grey hair to "play something modern." About twenty seconds later when Britta throws her tea hat off towards the pianist, however, it's an entirely different piano player now, that has brown/black hair. (00:17:10)
Continuity mistake: Near the end, when Jeff says to Troy "you're a man now" the camera goes onto Troy and we can see Abed asleep on Britta's shoulder (Britta is also asleep), even though in the shot before that, they were both awake. Then after the shot of Troy we see Britta and Abed awake again.
Continuity mistake: Abed is making a documentary, and we see the fact that there are two cameras throughout the episode, so they are definitely acknowledged. However, in the scene at the trout fisherman's house, there is someone filming behind Annie and Troy and towards Annie and Troy. The problem being that whenever it shows Annie and Troy in front, there is no cameraman behind them, but when it cuts to behind them again there is somebody there filming.
Continuity mistake: When Annie starts to throw her tantrum, she knocks stuff off the table, including the microphone and small mic stand. When she's lying on the table, the mic stand is back on the table. It back on the floor when she and Jeff leave, although the Uruguay sign is now back on the table.
Continuity mistake: When Britta is in a cage, before Chang walks in, a couple pass her and are walking out the double doors, where both doors are open. After Chang steps up to the cage and the camera shot changes, the couple is further away from the doors and walking out again, only this time one of the doors is closed.
Continuity mistake: After the pottery class scene, in the Spanish classroom, when Britta and Jeff are talking, his right arm is across the desk. When Jeff replies "so did someone's psych teacher" and camera cuts, his arm is suddenly folded up by his chest. In the next shot, his left hand is suddenly over his right hand.