Felony C, ual misconduct with a minor?

My friend was charged with a felony C with a minor, although the allegation is not true he had to leave the country? Does he get charged even though there was no investigation? will he have trouble getting back? how can he clear these charges by being outside?He is innocent and the girl lied about her age, told she was post 16 when she was really 14? this was all in chat and there was no physical contact. She is just getting back at him for not being friends with her anymore? he fled because he did not want to do any jail time even when it was getting cleared? what are his best options?