I cant go into graphic details, but gangbangs have unavoidable male-male contact. Im sure the victims would be traumatised being turkey slapped. Being drunk and underage they couldn't consent. Even if they did enjoy it at the time it can still have lasting negatives on their lives.
Its mucho to think they're boys, I would have loved it. Girls are different, etc. But some guys would also regret it afterwards.
I agree that her age being only 20yo helped her cause. And not being a teacher too.