They didn't, but it's a bit of an optical illusion, because the reel doesn't extend quite to the end of the combine header. You can see the point of the header around the grain cart, there's no strip missing behind them, and it's being steered by GPS.

GPS drift does cause little single row strips sometimes and they do look awful, because they usually get left until the next growing season.

yea seems a waste of fuel to go back to get the thin strips that are missed.