Sabrina - I am genuinely worried that my own experiences seen so out of whack with the experiences of so many on these threads, and I have been contributing for many years now.
Fwiw - as far as I am concerned, courts have been crystal clear since the seminal case of Re L in 2000, which relied heavily on the reports of Drs Sturge and Glaser, that violence was a failure of parenting and the violent parent had to understand this, cease being violent and make reparation (if possible).
I still wonder whether what is going on is that of course we don't conduct our lives with one eye on a future court case, we don't gather evidence of each incident of abuse and shame and fear keep a lot of women from reporting.
So all I can say is if you are with a violent man, get photographs, document your complaints, complain as soon as you can.
there is really very little for e.g. a court can do with an allegation of rape which is years old and the relationship has been on going in the meantime and there is no other evidence but the assertion of the alleged victim.
this doesn't mean the courts are a bastion of misogynistic women haters - it means that decisions can only be made on the evidence. And in this particular case the judge decided there was more than enough evidence to make serious findings against this mother's competence as a parent. If she thought he was wrong, she should have appealed, not run. She has just made a crap situation 100s of times worse, for everyone but especially her son.