Her hair was entangled in the tape and the tape held the mandible in place, which normally falls away. Since it held the mandible in place it had to be right there.
I've considered the swimming accident theory quite carefully but it always falls through with the time lines and other factors which throw it out.
I still say those who believe in the swimming pool theory should start a thread and see if they can make it fit. “Prove” it was the swimming accident.