It could still be the finish line, because if it's both the start and finish line, most likely the sign that says "finish" will be at the opposite side.
Those frames with Luke can be interpreted two different ways:
* Luke hugging himself looks like he's just starting and is a bit nakedness-shy.
* Luke with fists in the air looks like he just finished the course.
I agree with Hakushu8. It looks like the race is finishing at the start line, common with circular or approximately so courses.
I have a question. If the start line and the finish line is the same place, why is Margie riding off in a cab? I was all for the single START/FINISH line scenario with the tents for warming and changing clothes. But that pic of Margie in the cab makes me think that there is a START line and a different located FINISH line. I think Margie is taking Luke's clothes to the finish line.
I think the pictures of Luke (just above) are at the finish line and the pictures of Jen (page 1) are at the start line. There is also a building behind Luke and there is nothing behind Jen but blue sky and a park. I am talking about a building that is perpendicular to the building with the blue portico that is behind Luke.
The warming/changeing tents are located at different places. In Jen's pictures, the tents are in FRONT of a blue portico. The portico has two levels of steps from the street level to the door level. In Luke's pictures, the tents are BESIDE the blue protico. This portico has no steps and is at street level.