I've seen a bunch of videos from Western States this year of people finishing, and they all seem to be walking across the finish. Jim Walmsley, who won in a course record, was moving at a pretty good pace for the final 100m or so and then stops right before the finish and walks slowly across. Is this part of ultramarathon etiquette, or is it exclusive to Western States, or is it just simply a coincidence that many finishers seemed to do this? Obviously the couple seconds that you lose don't matter over the course of a race that long, and the runners are certainly exhausted, but what's the reasoning for this?