Factual error: At the end when Ms. Finster tells Randall to give her the names of the kids involved with the ball incident, she says to list them in alphabetical order. The first name Randall says is "Dettweiler, T.J." But "Blumberg, Mikey" would actually come before that, and given what we know of Randall, this isn't the kind of mistake he is likely to make.
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.
Suggested correction: This is literally just an assumption, and nothing else. 4,362 is a pretty huge number, and with the amount of cans that we see the Ashleys collect in the episode, combined with the amount of cans that they and the rest of Miss Furley's class collected off-screen, it is perfectly believable that Miss Furley's class would end up collecting that amount of cans.
Continuity mistake: When the kids are fighting over the can at the celebration, the can keeps swapping between green and red between shots. There is also one shot where the can is red but turns green twice in two frames.
The Great Jungle Gym Stand Off - S1-E21
Other mistake: 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.
This correction misses the point of the mistake. In "Recess: All Growed Down," when Gus moves to the school, the kindergartners are shown as "normal," but then Gus changes them to be wild, and they start to have torn clothes and paint on them. However, in the flashback scene in this episode, it shows the gang meeting on the first day (excluding Gus), and they have torn clothes and paint on them. This doesn't make sense because they only became that way when Gus moved to the 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.
Continuity mistake: When Dr. Quilty is filming Gretchen in front of the Kindergarten Area, Gretchen puts some candy in front of the door. When Gretchen runs away, the candy has vanished.
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?