Full Moon / Student Teacher - S4-E1
Revealing mistake: Student Teacher: When Olga says, "But, nothing, baby sister!" before giving Helga detention, Rhonda and Brainy disappear for one frame. (00:17:17)
Big Gino / Jamie O. In Love - S4-E2
Revealing mistake: In the cafe, after Charice speaks, when Gerald says "Aloha, Gladiators on Ice", there are three places where Gerald's mouth disappears.
Dinner for Four / Phoebe Skips - S4-E5
Revealing mistake: When Helga and Phoebe leave the girls' bathroom together near the end, Helga pushes the door outward, but the hinges are on the inside, so it should only open inward.
Answer: The episode doesn't really elaborate on who the kid was and what his motives were, so its pure speculation as to why he took it. Perhaps the kid could simply want a ball all for himself and decided to just take it, or was simply a rotten kid. The truth is the kid's motives are not important to the story other than it highlights Arnold was having a lot of trouble getting through the list.
Lummie ★