It is, therefore, only possible to analyse based on what we have.
Here is a still from the video on You Tube. You can quite clearly see the supposed humanoid form sitting in the background.
Cropped and showing "scale" between alleged Yowie and the men to the foreground.
Now here is an enlargement of the frame showing just the "Yowie". Huge, bulky with a withered left arm. At least it is what you think you see. Look around this "Yowie" and you'll see matrixing or Pareidolia and there is a good article about this on Wikipedia: http://en.wikipedia.org/wiki/Pareidolia
I have to write that based on this image nothing more than matrixing is involved. Think about it: the photographer took his photo but did not see -some 10ft/3m?- a huge humanoid creature sitting there? If the distance between the men and the "Yowie" is around 10ft then it must stand a good 8-10ft tall -sitting about 5 feet (1.5m)?
How on Earth could you not see that??