Welcome to the forum. You have indeed chosen a very heated topic in which to enter this forum LOL. But seriously calling horses beligerent and disrespectful is a commonly term used to describe horses that don't respect the chain of command. I suppose that is is anthropomorphizing on some level but horses respect leadership. In their natural setting the lead mare or the stallion would be incharge of the herd. Our job as owners is to let the horse know that we are in effect "the lead horse". Horses that don't get that needed leadership become "disrespectful and belligerent" to humans. This behavior can take many forms and some-of them can be extremely dangerous. Anything from biting, kicking, pinning ears, charging , striking and much more is commonly attributed to horses that do not respect humans as the leader.
Enjoy the forum, I'm sure that you will enjoy it if you start on any other topic ;) there are a lot of serious horse lovers here and at the end of the day we are all very sad for Misty. She is the main loser in that court room.