Unless it's something that happened during Breaking Dawn (which I disliked and so only read once), I have absolutely no memory of him abusing her D:
Unless you're talking about him accidentally scratching her when he transformed. If आप are, that can hardly be called domestic violence! It was an accident :) The two of them were in a forest having an argument, when Emily कहा something that made Sam lose his temper, and begin to transform. He had less than a सेकंड to react to what was happening, so he tried to hold his hands up to warn her away. She misunderstood, and thought that he was just trying to tell her to be quiet, so she stepped आगे to continue the argument. When he transformed, he suddenly took up so much और अंतरिक्ष that his hand (or rather, claw, now that he had transformed), which was still held out to warn her away, scratched her.
When Sam hurts her it wasn't intentional he just couldn't stop himself from doing it. It is कहा in the book that वेयरवोल्फ can't control themselves when they are angry, so Sam can't control his violence, I mean he is a werewolf (or shapeshifter)