Breeding Farms and Mistaken Identity

One of today's callers had a very complicated situation involving a horse that had been switched at birth as a foal on her breeding farm. The foal's true identity was revealed only when its DNA was submitted for registration over a year after it had left her farm.
What can breeding farm owners do to protect themselves against situations of mistaken identity? The caller and our attorney discussed this question, resulting in the following suggestions:
-As soon as each foal is born, take a digital photo that clearly shows the foal's markings and keep it in the mare's file.
-Rather than having the client take the DNA sample and send it in to the registry for testing, do it as early as possible (and before the foal leaves the farm). Specify in the mare care contract that the farm will perform this service and the client will be required to pay for it.
-Include a clause in your mare care contract limiting liability for all claims to the amount paid by the client under the contract.