I think you are safe, I checked the photos, and cant see you on there.
What is really weird though, is that your number was 152, so you must have registered just before 10am, cos my number was 151, so I would have been right in front of you! I would have rushed in and out again though, cos I already had the form filled in, and when I had registered we went out to check the course, even though I had run it before.