I think you misunderstood how a photo finish camera works. Please try re-watching the explanation video. The photo isn't a snapshot of the race at a specific ti

I think you misunderstood how a photo finish camera works. Please try re-watching the explanation video. The photo isn't a snapshot of the race at a specific time, the photo shows an entire interval where the top cyclers passed the finish line. It's like having long shutter time and a narrow slit and slowly moving the camera such that you get the view of the slit projected along the entire camera sensor.