This was true to a sad extent. A dozen men out there on the street after midnight, a crying women and all of us armed with guns, knives, baseball bats...... and she said no, she was just crying and don't hit him.
And out of the blue this followed.
We aren't always there. I've brought guns and knives to the "No NO NO! a time or two. One feels
a little silly standing there armed to the teeth for confrontation and hearing, "no no". We persevere and say, "just you stand up and come to my side of the street and say that, that's all and I'll go away." And they do and you go back inside.
Some of us were raised on the story of Kitty Genovese and we are not ever going to let that happen on our watch. But it ultimately isn't our call. In the half dozen calls I've never once had the girl accept our offer of help. On the other hand, each case seemed to resolve without violence then or later.