Agreed, KV. I just realized that I forgot to mention that. There are some horses that freak out when it's put on.
Wow, that first guy was completely out of line. My brother is always very careful to ask 2 or 3 times "Would you mind if I gave this a shot?...Are you sure?...You're sure you don't mind?" and he hardly ever uses it unless the horse is borderline unmanageable or appears to be getting close to that point. Even if he wants to use it, if the owner says "no" then he agrees and tries to do his best anyway.