Well, you can pinpoint the problem with the woman in the relationship itself. Not that the men is not to blame, disappearing with no goodbyes is just rude. When you two started dating, the girl would tend to be more easygoing and laid back. She is still at the stage that you want to explore the possibilities with the man and see if he is worth the time. Starting out was fun and enjoyable, you two seems to like each other enough. After a few dates with a guy, most women start to rush a little on the possibilities for a long-term relationship. So, girls start investing in the fantasy of future together.
She is now no longer in the date for what it is, but for what it could be. That is the problem, instead of focusing on the present, she is distracted by her own fantasy. She starts stressing out, afraid of losing something they never really had yet. This insecurities and fears would only seep into the dates and her interaction with her “future” partner. Rather than trying to be with the person right in front of her, she stayed with the illusion in her head. She is busier about how their distance in the relationship is currently at, rather than focusing on the guy, and so he left since the girl he though he knew turn into an emotionally imbalanced and attention seeking.