She got the scare somewhere. How hard would it be to push her in her training, and make sure she takes beatings on the grounds of "if she feel pain in the training, she'll remember what to do to not feel that pain, and it will save her life, so it's for the best." when in reality all your doing is beating a mostly defenseless child because you can, and making sure others will have a harder time calling you on it.

And hell, he doesn't even have to be physically abusive, words can screw a person up if there the right one's with the right tone and context at the right time.