Pretty much every dog owner on this sub, myself included, believes that the dog would have followed her into the water based on our experience with our pets. As Willow actually liked the water, it would seem even more likely that she would have followed NB in.
This doesn’t necessitate a third party, she may have fallen in while the dog was exploring and didn’t see her go in. Or if the dog pooped near the water it might have taken off afterwards (they seem to regard their poop as some alien thing they need to get away from, or at least most of the dogs I know do) and NB may have tripped and fallen in while trying to retrieve it. In that case the dog would return to the phone and hang (as it seems to have possibly done).
Or, she was taken by a third party and the dog is indicating the direction they went (I.E. the gate). Because, again, as a dog owner around a lot of dogs, they do tend to wait where they last saw their owner.
It isn’t necessary to know and exact dog, to understand the behavior of dogs in general. I don’t think folks are being crazy here when they extrapolate from experience with dogs,
