Near the end, when the boys have left the barn, and are being loaded into the van, there's an initial shot showing the final person enter the van, and the side door being closed. After a short cut to another shot, the van appears again, with the side door now open again, and people still being loaded.
When the police are first shown arriving at the barn, it cuts away with the cruiser roughly two car lengths behind Nathan's truck, with the truck stopped and the car still moving at a decent pace. Twenty-five seconds later, it shows the cruiser still pulling up behind the truck, slowing from approximately the same speed, not the extremely slow crawl that would be required for it to take so long to cover this short distance.