Amber's ex wife has stated time, time, and time again that Amber was never abusive towards her.
Although we can't possibly know for certain if this is true, everyone seems to believe Wynona Ryder when she says Johnny wasn't abusive towards her. I believe Wynona, abusers dont have to be abusive to every partner.
Tim Burton made it clear that he did not approve of Johnny's behaviour towards Kate Moss when he was dating her.
Its not uncommon for victims of abusive to eventually snap and lash out at their abuser, and the abuser then uses this as evidence that they themselves are being abused.
Does anyone remember the Little Mo story line in EastEnders?