i don't think she was abducted, i think she chose to go according to the pictures that were taken of her and the teacher.
I spoke to my Dad about this (he is a Solicitor) and he said because she is under the age of consent- it's abduction, doesn't matter whether she went willingly or not. The age of consent in France is actually 15- but there is some european law which means that they can arrest him over there because she is under the age of consent in this country if that makes sense.
I feel really sorry for her right now- she is on her way home, he is off to court and possibly jail. She will be heartbroken because she thinks she is in "love".
On the actual situation- I don't know, I really don't. At fifteen I know I had a lot of growing up to do still.
What makes me REALLY sick though is that this guy had tried it on with someone else, as did another 2 teachers at that school. I don't think there will be many prospective parents for the school next year.