Rape is definitely a case by case thing. Every situation is different. That's why there should be no set penalty for any cases. Everything is different.
Rape is a really bad thing. It can be emotionally devastating and mentally scarring. What sucks about it, is that it indeed is really hard to find out what actually happened with the two people. Almost every time alcohol is involved and there are either very few or no witnesses. It really all comes down to the history of the people in the case and personalities, and that's sad to judge a case based on a speculation of someone.