This is a panorama of the sand bar in the very first moments of the filming.Click on the image to animate it.
Copyright Patricia Patterson. Film work and stabilization by M.K.Davis. Please do not right click without permission.
Here’s a repeating file of the very shaky, earliest part of the filming. Click on the image to animate it.
Copyright Patricia Patterson. Film work and stabilization by M.K.Davis. Please do not right click without permission.
This file shows something falling away from the left leg of the film subject. It’s hard to tell what it is. What do you think it is? Click on the image to animate it.
Copyright Patricia Patterson. Film work and stabilization by M.K.Davis. Please do not right click without permission.
The Davis Report 
I was just looking at your animation of “something falling away from the left leg” and to me, it looks like the creature is stepping on a branch that is pushed forward and down under her weight.
I think that’s a good possibility. M.K.
It looks to me like her shadow?