Midnight Rx - S16-E6
Corrected entry: The towel Flanders wraps around Apu's head changes shape between when it is first applied, and when the customs agent sees Apu. First it is an almost perfectly round shape with no loose ends, then it becomes a more flat shape with a loose end hanging over Apu's shoulder. When Apu is seen inside the police van, the towel is once again in the original shape.
Correction: Since it's a towel, and not an actual turban, it's not a surprise it loses shape and comes apart. And there is time before Apu is thrown into the police van for him, or one of the others, to have rewound it.