So you can see it is very important for your horse to behave, it is your job as the handler to see that he does. This is what the handler must watch out for, because he may have to pull the horse off of the farrier in an instant, and at the same time keep himself and the horse from getting hurt. Don't set yourself up to be pinned against a wall or fence, there must be somewhere for you and the horse to go if the horse is being unruly. The handler is the most important part of the shoeing team. So if the handler is standing in front of the horse instead of at his shoulder, he is in a position to get seriously hurt, and not in a position to control the situation and keep everyone safe.
Some people complain when farriers charge more when a horse acts up when being shod.
The farrier is taking a chance that he or she might be seriously injured. Let's say the horse stood for the shoeing but, as I go to finish and rasp down the clinches before I clinch them over, she decides to rock or climb on the foot stand. The handler needs to be paying attention here too. Pushing the horses nose backward toward his chest will keep him from throwing his weight forward, tipping his nose toward the handler will put weight on the foot he is supposed to be standing on anyway. Some horses will paw the stand.