Just before the "Bust Your Windows" segment Mercedes throws a rock at the windshield of Kurt's Escalade. The rock goes right through the glass into the car. The windshields of all contemporary cars (like Kurt's) would not behave that way. These windshields are made of laminated glass that cracks but does not break so easily, and would not allow a rock thrown from a few feet away to penetrate it.
Finn mentions Jim Abbott, the "one-armed" pitcher who played for the New York Yankees. Abbott is not missing an arm, he's only missing his right hand.