The details of the crime seem a little sketchy. This chick was partying with her little sister, got smashed , was making out with this guy, and ended up behind a trashcan with this dude (who was also smashed). The chick didn't even know she had been raped until she read about it on the news.
From what I have heard of the case, it sounds like it could have easily been a case where Drunk Chick A starts having sex with Drunk Dude B and then passes out in the middle of it...magically turning Drunk Dude B into a rapist.
There isn't enough story for me to demonize the guy just yet, and perhaps this was the reason for his lesser sentence. It could have easily been a case of the "morning after regrets"