No! This is NOT a big deal. It is only being poorly dealt with.
You can only tie a problem horse with a good, strong nylon lead-rope and it has to have a swivel snap. We have 3/4 inch nylon ropes with 5 inch bull snaps that have a good swivel in them.
If you use a tree limb, it should be at least 8-10 inches in diameter where you tie the rope and let it hang down. An ideal place would be a big over-hanging limb that is 10-15 feet off of the ground. Then, a 5/8 to 3/4 inch nylon rope it tied solidly to the limb with the snap end hanging down to a point about 4 1/2 feet above the ground. The rope would ideally be 8-10 feet away from the trunk of the tree.
The horse's halter should be snug and fitted well above his nostrils. There should be only 1 rope on the horse and there should be no way that he can get into position where the swivel cannot turn around freely as he makes little circles under the tree.
When you have a place like this to tie a horse to a tree, then LEAVE HIM ALONE. Do not put a second rope on him. Do not stay where he can see you. The object is for him to learn to stop pulling, fighting, worrying or getting upset. The object is for him to learn to accept standing quietly all by himself.
This is a valuable lesson that any trained horse should know. A horse has to stand tied to a trailer at any 'haul-in' show, rodeo, roping, team penning, sorting, cutting, or even a dressage show. Heck, every horse brought to the local two bit County Fair has to stand tied most of the day waiting for classes.