This is a valid point. 20 years is the maximum age to insure the life and health of a horse, and by that time any remaining market value lies in their ability to breed. If I owned this horse, I'd retire him to stud.
I think this situation was summed up best by Rachel Cox, cited in the story as a Pennsylvania horse farm owner and board member of the Irish Draught Horse Association of North America. "I've seen this so many times," Cox said, referring to misunderstandings among owners, breeders and trainers of expensive horses. She said owners underestimate the effort trainers put in, trainers can get very attached to specific animals, and friends frequently don't execute the proper paperwork. "You really need to cross the T's and dot the I's."
If it's not written in a binding contract, someone else is going to decide. This bitter dispute could and should have been avoided by confirming all agreements in writing.
It’s ironic that people think negotiating a contract with a friend will jeopardize or ruin the friendship. But that is nothing compared to the bitter acrimony, enmity, and outright hatred that results when the deal without a contract sours and goes to court.