Audio problem: When the boys are beating up Mikey during the flag football type game, he knees one of the kids in the crotch. An African American boy then says "man you should start wearing a cup." The boy's mouth doesn't match.
Audio problem: After Bobby says the "F" word, he says "someone get me soap, I'll do it myself." His mouth doesn't match.
Answer: Deliberate production choice, and to show him from the younger child's point of view - also remember The King, when in his drunken state, is a child abuser, so the younger boy will see him as a large and terrifying presence - that is, so big he won't fit in the frame of the shot.
Neil Jones