She sure is a horrible excuse for a trainer, but abuse-NO.
If the person behind the camera knows so much why not help? Just a thought. If you stand by while you really thunk a horse is being abused-you are just as bad as the abuser.
Again, this is certainly not a method I would use, but now the horse is desensitized to wiffle bats! And yes, OP-had that bat been a whip-I would have had an issue..But I am more apt to go help.