I'm not trying to pick at this, but if you were at the barn and he did something nasty, would you accept punishment from someone else then without your permission?
Nope. I would blow a fuse if someone hit my horse.
I pay the barn to take care of my horse, to make sure he is fed and safe. I do not pay any of them to be my horses trainer, or disciplinarian.
There are quite a few naughty horses at the barn I am at, and the men who work there are large and big and can handle any situation that occurs, but NEVER have I EVER seen them hit a horse.
Most of the handlers can get the horse back under control and continue on doing what they were doing, to ensure that the horse and other boarders horses are not in danger.
If my horse was being naughty, they would never discipline him in the manner others here would think - which is striking at the horse - they would just calmly and cooly ride out the scenario and move on.
IF ANYONE jerked my horse in his mouth, or hit him or struck him for any reason what-so-ever - I would rip them a new one, and move to a new barn.
It is absolutely unacceptale to me, to hit a horse that does not belong to you.
I have been asked my boarders to help work with their horses, for instance, I worked with a horse that is hard to load, and I had some pretty interesting situations occur, but not once did I hit the horse.
I've had horses ram into me, I've had horses forget my presence and walk all over me, but I don't hit them. I use my body language to fix the sitation and that works well for me. I learn to read the horses body language to keep one step ahead of the animal.
And I if I see a situation that boarders aren't privvy to picking up on, I'll shout out "Hey, don't let your horse do that, because this is going to happen" and they quickly stop doing what they are doing, grab their horse and move them into a different position to prevent what may occur, from happening.
There is no need to hit someone's horse. There is no need to jar a horse in his mouth.