My first reaction was the video contradicts the song (which I really like). The images are a murder ballad narrative while the lyrics, as far as they imply a story, are about an impulsive act of pride:

What do you expect me to do
If you're playing me for a fool
I will lose my cool
And reach for my fire arm

I didn't mean to lay him down
But it's too late to turn back now
Don't know what I was thinking
Now he's no longer living
So I'm 'bout to leave town

'Cause I didn't mean to hurt him
Could've been somebody's son
And I took his heart when
I pulled out that gun

This remorseful and bewildered killer seems to offer a direct anti-violence lament, which clashes with the rape and revenge illustration. For me, the dissonance slightly implies, unintentionally, killing a rapist is just a rash act of wounded pride. There's also the dubious attempt to have it both ways, the usual sexy dancing/flirting and a dramatic rape story. Overall it seems more about the themes of Rhianna's life story than the song.

Perhaps such contextual sloppiness feeds into the politics of those trying to ban it: i.e. a sexy girl attracts rape then reacts too harshly.

I believe commercialized provocation is an essential part of pop music's art. In this case, good intentions and cynical calculations both seem clumsily grafted onto a song which is strong enough on its own.