From books and newspaper articles I've read and stories I've heard about this part of the world a scenario quickly forms in my mind:
Public nudity here, especially for a female, is probably meant for the purpose of deep, profound shame. There are stories of girls falling in love with someone that her family or community doesn't approve of and being paraded around nude as punishment. It doesn't even mean that any sort of relationship happened between the couple, just that it was considered. There are lots of possible reasons, but most of them probably involve the girl being considered somehow immoral.
Also acutely alarming is that she had probably already been subjected to some form of molestation or rape as her real shame. The walking around might be to make others aware of what had happened more privately to her as the 'culprit' and enhance her shameful feelings.
What was done to to her would linger long in the minds and on the tongues of the members of her community who witnessed it and the feelings of humiliation would go on and on. Unless her family was not involved and gathered around her to be supportive after and unless she was already a product of the sex trade, there is a statistically probable outcome....that she would then be ashamed enough to kill herself.
I am theorizing here and have no idea what happened to that particular girl. I hope I'm wrong. We routinely see situations of injustice and as foreigners have to wade through the tricky waters of quickly deciding 'What should I do?' when far too often there's not much to be done because as outsiders we'd likely make it worse for the targeted person in the long run. Steve by himself trying to grab a naked women even if to help her would be incredibly culturally taboo. It would incite rage in an even larger crowd which would probably later be turned back on the girl as the one who 'started the problem'. There just aren't easy solutions. And in our western thinking we can easily make wrong assumptions to start with.
In a city so full of needs you have to know what your focus is. Even though it's confusing, we're glad that we're here and glad that we get to be part of something that does provide freedom and brings about change. Because in our area young girls are shamed, abused, dehumanized, and abandoned every day.
Note: I've been reading the book "Half the Sky" by Kristof and WuDunn who are secular journalists. It's a very good overview not only of trafficking and modern day slavery around the world but it covers other women's issues as well. I don't agree with all of their conclusions, but they have a lot of valuable insights.