I have only read what you have linked to but, yes, I do think the role of both parents should be taken into account, particularly where there is a history of domestic violence.
I don't know abut prosecuting him for leaving them but I would expect there to be some consideration of his role in the mental health issues the mother had and the impact that would have had on the family as a whole.
Certainly, if my husband andi split up and he had part or whole custody of the children and I had any suspicion that he was treating them in the way this woman was I would be doing my best to get them properly looked after. This article doesn't show if the father actually did attempt to do that so can't really judge either way.