When Nick enters the cornfield there's a spot on the back of his jacket. Next scene the strap on the pouch is covering it.
When the car is driving fast on the road by the sunflower field, it is kicking up a lot of dust and continues to do so when it drives on the plowed portion right by the sunflowers as it stops. When the passengers get out of the car, none of the dust from their rapid speed in the field behind them nor on the road is visible.