Teenage girls raised in good homes, protected and pretty sheltered, don't have that instinct one gets over time to watch over the shoulder, be careful who you talk to, don't accept men at face value and so on.
That said, I once, at age 59, came out of an airport late at night, tired from an all day flight, and got right into a white car that a man in a uniform was standing by, assumed it was a cab. I had a close call and only was unhurt because I put my hand in my carry bag searching for my cell phone when I realized his intentions. My cell was not there {packed} and I froze with my hand in the bag. He kept looking at me and then brought me to my daughters home unhurt. It was only later that I realized why I was unhurt,,he thought I was carrying!!! My son in law told me that.
THe point is, I am a safe, observant, somewhat paranoid travelor {my kids say I am paranoid} and I had lapse, a small one. And escaped by luck and I know it can happen to anyone.
However, in a group, with peer pressure to be a bit cavalier, anyone becomes very vunerable. She was an easy target because she willingly left her group of friends. I don't think she is to "blame" for what happened, but it just proves that unwise behavior can lead to tragedy, and one should never take chances in a strange place, with people who are not well known.
What a story...how frightening and how wonderful that you arrived safely.