I find it funny how many people think that this was a fitting or fair punishment. Not trying to justify rape at all, but mutilation is not a fitting punishment. It's a rather selfish way of looking at things.
If we all are to say that this was "justice," then I suppose that theft should also result in mutilation. Petty theft? Rip off a nail. Take it one step further? Cut off a digit. Then up and up until you cut off both of their arms.
This is the line of thinking you guys are going with. It's pretty medieval.