How it happened

Katelyn explains that while she was leading the race someone motioned her to a route that ended up being wrong, shortening the track and incurring for her a penalty she couldn't overcome, so she retired from the race, not a happy rider.
UPDATE (via email from Katelyn): "I did end up winning that race. A track worker pointed me a line with many other riders and they ended up adjusting the time because of their error."