I'd tell them that he is probably stressed. It will take around a week or 2 for most horses to settle in. More, if they have never been off the farm. Plus, they haven't had the horse long enough for the horse to get to know them, bond with them or trust them.
When I got Fanny (my new horse) here, I gave her a week of just walking her around the property, hand grazing and grooming her, to allow her to get to know me, and settle in. Then another week of longeing. Then I got on her after longeing.
With a 3 yr old, they need to slow down, and spend some time on the ground with him. Trailering long distance is stressful, and hopping on a green horse without time to settle in is just plain stupid. Have these people had young green horses before? How "horsey" are they?
I'd almost say take the horse back, just because they don't sound like knowledgeable horse owners. Have them pay the shipping back and refund their money.
Did you specifically tell them that he was "wild" at first in new locations & that he needed more time to settle than others might be?
Regardless, if I were in your position, I'd take him back & refund them their money. The horse world is a small one, & I can see already that the feedback from their supposed experience with you will run rampant otherwise. Not to mention what might end up happening with the poor horse.
I love this horse and never would have sold him if I even thought for a second this would happen. He has never acted this way.
He is wild the first day at the show and I would lunge him for the first few days, but I never had a problem with him.
I was very honest with them about everything he is so the fact they say I was not is just really frustrating.
My bolding - Did you tell them that? Exactly that? Or did you say he was safe & sweet? You say "he has never acted this way" and then you turn around and say "he is wild the first day at a show"...
It is not necessarily "normal" for a young horse to be "wild" at a show. A bit nervous, rushy, a bit looky, sure. But "wild"? That's not normal.
Did you, or did you not, tell them that he is "wild" at first when he arrives in new places and needs time to settle in?
If they thought he was fine in new places, then they have every right to be appalled at his behaviour and p*ssed at you.
Now, i do agree that after 4 days on a trailer, it's not really fair to expect 100% calm, happy behaviour from a young horse. But rearing and kicking at people? That's extreme, and unacceptable. If he had simply been a bit rushy, spooky, or balked a bit, then I doubt you would have gotten such a strong reaction from them.
And a horse that has never, ever even *hinted* at kicking at people does not simply start kicking because it's stressed after a 4-day trip. That is also not a "normal" reaction. He should be a bit aloof, a bit skittish, maybe a bit resistant, but not aggressive & dangerous.
Another possibility is that the horse suffered some mild trauma on the trip - while on the trailer, while being handled by the hauler, while in a strange place for overnight'ing...
In any case, i hope you were 100% honest and I hope they're being 100% honest as well, and i hope this works out for the horse - whether that means you taking it back, or them giving him some more time to settle.
Not once in my 39+ yrs in this industry have I heard of someone *successfully* purchasing a horse off of video alone. There's usually an agent that goes and rides the horse on the buyer's behalf, and/ or the seller has someone in the neighbohood of the buyer to check out that they're legit.
Granted, my experiences are with horses $5k - $25k..
Sorry for your tough situation. I had a lease go sour before so I can sympathize. I also thought it was the perfect home. Only lasted about 6 months. I ended up paying for the horse to be shipped back to me. If I were in your shoes, I would request a video of his behavior. I would honestly want to see for myself what the horse is doing. If they are that upset they should not have a problem taking a video on their phone and sending it to you. And if they are lying about the behavior to return a horse that is not what they wanted, then you will know. Make your decision from there. But if you want to know where the horse ends up, you will have to take him back. They will most likely get rid of him to the first buyer that comes along if you don't.
What if you ask them to fly you out so you can see what is going on and find a possible fix?
A few years back I sold a friends horse for them and the new owner was having a "bucking and bolting" issue. The horse had moved 1200 miles from me (I started her under tack and at first shows) I was flown in and rode the horse for a couple days then gave the new owner a lesson and though they still had some issues a month later at least it gave them some tools to help owner's instructor work them through it again.
Flying out is a whole lot cheaper (and easier on the horse) then shipping the horse back for what could be a easy fix.