The hole in Bart's pants disappear in between scenes.
At Milhouse's trial, Nelson and Terri disappear at one point.
When Bart gets a bag of OREOs from the cooler, it turns to cookies when Lisa takes it off him.
When Milhouse is on trial, Lisa calls Milhouse and he pulls his cage towards Lisa so he is a few feet away from her. In the next shot, she is standing right next to him.
When Bart, Lisa and Milhouse are running from the others, the order is Bart, then Lisa, then Milhouse. In the next shot, the order is Lisa, then Bart, then Milhouse.
When everyone is eating the boar, you can clearly see nothing has been cut of the boar.
Most of the time, characters on the show's eyes are drawn very large and connected to each other. But during the Model UN scene early on, Bart is seen wearing sunglasses and a strip of skin mysteriously appears between his eyes whenever they are on. But his eyes suddenly are large and connected again when he takes them off.
Before Bart goes to get the cooler of snacks from the bus, Bart takes Milhouse's inhaler and Milhouse says, "Hey, I need that to live", but his mouth doesn't match what he is saying.
Homer doesn't fully understand what the internet is, and that it can be accessed by a computer until he reads about it in a book. Yet, earlier on, he somehow had a pop-up add online that catches Comic Book Guy's attention.