I agree with everyone else..
OT I know, but I just have to tell you guys how stupid people are.. I used to work at a riding centre (in Australia) and they used to put side reins on the ponies the kids were riding to try to prevent them from eating the grass!
Are you sure they didn't use side reins when riding to protect the horses mouths from unsteady hands ? This I have seen and in these cases the beginner riders will get the proper feeling and learn to sit the horse/pony while the animal will not have jabs and pokes in the mouth.
The first riding lessons I ever took was from a German master that used side reins while we were riding and I didn't know why until much later.