Neither the abduction theory or the falling in the river theory stack up to me. But it’s got to be one or the other.
It just seems very unlikely you’d fall in being fit and healthy, and furthermore then be unable to get out. And on top of that, if that did happen, for the body to then not be in the area. That doesn’t make sense.
Likewise it doesn’t seem very plausible someone could just approach someone who’s on the phone in broad daylight and take them away without a trace.
One of them has happened though.