Several Grey Mulga were identified further north closer to Fed Highway; Greg Baines identified Grey Mulga among the plantings along Federal Highway Acacia brachybotrya (Grey Mulga, Grey Wattle) A non-local native; I saw it in SA's Mallee woodland where it naturally occurs.
I still believe this is an Australian Darter. 1 - the bird has red feet whereas the little pied cormorant has black feet. 2 - the 2nd & 3rd photos show the white line through its face and its face is not fleshy and yellow. Also, see sighting #4713343 for a similar looking bird.