Pretty simple - the course loop starts at the very beginning of a straightaway on the widest section of the course - that makes sense. But that means that the loop ends on a curve leading to that straightaway and that doesn't make for a good finish. So after the last lap they have the runners run 110 meters more down the beginning of that straightaway to the the finish line.
It was only 110 meters and that was clearly stated before hand on the course section of the race website.
No problems. There were timing mats and markers so you could get every 1k split the whole race if you wanted to.