Plot hole: Near the end, at the assembly, the old lady sitting on stage can't even lift the turkey. But about 90 seconds later, she's running away from the can pyramid. What a miraculous recovery.
Revealing mistake: Right after TJ and friends are looking at the "thermometers" of cans, the Ashleys have at least 4 crates of cans that they bring in on forklifts. However, the end result is 4,362 cans for the Ashleys. This may seem kind of picky, but I think there was more cans than 4,362.
The Great Jungle Gym Stand Off - S1-E21
Factual error: When TJ says that he and the rest of the gang met at old rusty, it shows you a flashback and the kindergartners are wild, but they only became wild when Gus arrives later (as said in All Growed Down).
Suggested correction: It's not true. After Gus "changed" the kindergartners he was sent away from school.
Continuity mistake: After Mrs. Finster has her show of strength and is pulling Gus away, he still has the chains from the wheel on his arm. When the shot changes, the chains are gone.
Continuity mistake: When Mikey's music teacher gets engaged to the Spanish guy, her ring disappears between shots.
Revealing mistake: In the areas where the kids change the tape, when Mikey slides and Spinelli is swinging, they are both holding cameras. Who's filming them?