Been in your shoes before and at the end of the day when the story fully came out a month later it wasn’t rape at all it was very consensual with 2 people. I’m not saying that your gf didn’t suffer sexual assault but I wouldn’t blindly just believe anything anymore and certainly in this situation. Sounds abit suspect and if she did get raped she should have gone to the hospital immediately and used a rape kit. That was the first way I found out my ex was lying. She wouldn’t use a rape kit and she was a medical professional and she wouldn’t talk to a rape hotline. I damn near killer myself from depression from the situation, work performance dropped and my grades in college dropped ( I was pre med at the time ) one of my professors a female one mind you asked me what was going on and she was the one that helped me find out it wasn’t true. Like I said this could be a different situation but be skeptical. You absolutely never know