You know, this makes me wonder. You said his mom bought the horse from the boyscout "camp," right?
There could be two scenarios.
One could be that the camp bought him to use as a trail horse. These are not "Your version" of a trail horse, these are pack horses, trained to be numb to kicks, and don't know the first thing about backing. This could have been a well-broke horse before going to the camp, and the camp decided that since he does respond to pressure that they can't use him for their trail program. Which could very well explain his acting up, if he hasn't ever seen a whip, rope, etc, he won't know what to think... could be too that he doesn't have a "buddy" to ride with, as most of these camp "trail horses" are nose-to-butt-to-nose-to-butt, "follow the leader" horses, and don't need much technical "training," but the basics just to get by.
And two, there is a Horsemanship Merit Badge, and there are 10 or 11 stipulations one must meet, and can be found here: Horsemanship Merit Badge for Boy Scouts BSA
Note the last stipulation is this:
On level ground, continuously do the following movements. Do them correctly, at ease, and in harmony with the horse:
- Mount the horse.
- Walk the horse in a straight line for 60 feet.
- Make a half circle of not more than 16 feet in radius.
- Trot or jog in a straight line for at least 60 feet.
- Make a half circle of not more than 30 feet in radius at a jog or trot.
- Halt straight.
- Back up straight four paces.
- Halt and dismount.
So this horse could very well have a working knowledge of the correct riding, but that doesn't mean that the boy scouts do, and he could be all flustered.
It does make me wonder though, why did the camp sell him in the first place? Was it because he was a danger to the kids there? Was he too spooky? Was there no one qualified willing to work with him on the training he needed? (Which in no way am I saying there wasn't someone knowledgeable, maybe that person decided there was another horse that was better suited and would rather not spend the time with this horse...)
But you must understand the two things this horse could have been used for, and you must understand that whatever his "job" was supposed to be, he couldn't cut it, otherwise the camp would have never offered to sell him.
Hope this helps....