You're absolutely right. She is nuts. When the horse goes to canter, their first step out is with their outside hind leg, followed by the inside hind and outside front together, and then the inside front. She is probably trying to force the horse to pick up the right lead by turning his head to the rail because she thinks his first step should be with the right front. But by taking away the majority of the weight on the right front, this actually causes the horse to pick up the WRONG lead because instead of taking the weight off the back left so he can step out with it for the correct lead, you are adding weight. Sorry I know that seems a bit confusing but when you look at a horse transition from a trot to a canter, you will see that this is true. My advice to you would be to ditch the trainer and try putting him on the right lead by turning his head towards the inside drastically to start out. Give pressure with your inside leg and slide your outside leg back. Hope it al works out for you.