Hmmmm... read the story, don't think she was raped. I think she got it on with that boy, and got pregnant. After it was discovered she was pregnant, all of a sudden, to keep up appearances, it's "rape". I have a feeling that's why the guy was pardoned, everyone figured out what happened.
Part of the story that led me to this conclusion:
"Bangladesh's Daily Star newspaper reported that she was so ashamed following the attack that she did not lodge a complaint."
Riiiiight. No, I think she didn't lodge a complaint, because there was no complaint, there was a complaint after she discovered she was pregnant though wasn't there. The girl had a last romp before getting married, and got herself into trouble. That's my take on this.
Moral of the story, even in dark ages muslim countries, kids in their teens and 20's will go out and have sex.