Audio problem: When Josh is telling Ben Stiller that the candy belongs to Seymour Butts, his lips don't match the words he's saying. In the next shot, Ben Stiller responds, and his lips don't match the words he's saying either.
Audio problem: During the Apache Relay Race, the boy who is swinging down the rope screams. But if you look closely his mouth is not moving at all.
Audio problem: When Jerry gets back on the track after the MVP racer runs him off, the MVP racer says "Oh, shoot." His lips, however, say a swear word. (01:30:00)
Answer: Could be he was smart and was advanced several grades. Could be a combined middle school/high school that's just called a high school.
LorgSkyegon