I don't need to hear the recording to know her life was not in danger. She was on the phone with 911 for over 20 minutes, in the presence of the people who were there. It is common sense that her life was not in danger. Anyone threatening her would have taken the phone from her or terminated the call.
As to where she died, she obviously did not die at the clients house, or anywhere along the way, because there were at least 3 reports to the police as she made her way to the swamp. That leaves the swamp. IMO she either died where her stuff was and the body subsequently floated to the final location, or she dropped the stuff after getting mired to free herself, and died where the body was found. There is a time line which is clearly established which points directly to the place her belongings were found, and by inference on to where her body was found. There is no mystery here, just the exact details are uncertain.
It seems to me to be highly improbable that someone in the neighborhood would kill her allmost in their backyard when they knew police were likely on the way, then move the body to another point close by while leaving the belongings somewhere else. That simply does not add up. Given the choice between a probable scenario and an improbable sceanrio, I am going to lean to the former.
Why would she run to a neighbors house for help, then run away because a neighbor lived there? That argument doesn't make sense.