How does the judge decide a close finish?

Under Rule 65 of the NHA Rules of Racing:

• The judge (or an assistant or authorised substitute) must be in the judge's box from the start until the result is declared and the all clear given. Nobody else may enter the box or contact the judge during that time, except the stipendiary stewards.
• The judge decides on the horse's nose, unless it is not visible. If there is any discernible difference, there is no dead heat.
• The judge checks the placings against the photo-finish photograph. If the camera fails or the image is unclear, the judge may use the race film; if there is no film either, the judge decides from what they saw. The judge's decision is final and binding.
• After the race the judge names the first 6 horses (or more if the stewards ask). These placings stand unless an objection is upheld, but the judge can correct a mistake before the time for notifying an objection runs out.