Shortened for brevity.
I'm starting to think the same. IMO HG went willingly with JM into his vehicle. Perhaps he told her he was an old cabbie and would drop her off at her party. Perhaps she just wanted to go home. Don't know. But a poster a while back (sorry, I don't remember who) said something about how "abduction" can legally mean you were detained against will. So that's where I think trouble started. JM didn't let her go.
To answer another posters question, I have no interest in JM being innocent. Why I keep bringing up ( maybe she just wanted to be with him) is in response to posters precluding that as a possibility. you kinda excluded that by saying maybe he promised her a ride home or to her party. He very well could be a predator. I just don't know why we can't see the possibility she was with him by choice. She very well could have been attracted to him & wanted to spend time with him. To me this would be the obvious reason she was with him. She had the opportunity to leave him.