Was it a temporary or a final?
I had a FINAL protective order... *sigh* I don't know about the state that you live in but in NJ a woman that has a final protective order must still SHARE physical custody IF the father wants it. Also, once a divorce is in place NO "women's rights organizations" will help a woman behind the 8ball with an abusive ex.
The whole thing is a tragic mess, no doubt. Just the fact that you doubted anything was wrong because DYFS was there and "nothing happened" tells me that something, somewhere was fucked up. (Maybe I misunderstood your initial post?)
I've heard of women (yes, met them personally) who had lost custody of their children because their husbands would beat them and they refused to put the men out. Interestingly enough, all the women were befuddled because "he NEVER hit the kids." (Sound familiar?)
In any event, the whole thing is horrible. Often times the fixes are not so easy and perhaps more people should learn that the first and quickest judgment isn't always the correct one.
My heart REALLY goes out to the family. I hope the mother and surviving children get a truckload of GOOD counseling. If anyone knows, I do, they are going to need it. You will NEVER KNOW how dearly I regret being talked into dropping that order by my then-attorney.. NEVER.