Revealing mistake: When the people come to take the girls away, the mothers and girls run, with the camera in front of them. You can see the wheel tracks in the dirt from where it is being towed back.
Revealing mistake: When the three girls are at the camp for children after being removed from their home, they witness a girl being punished. She is having her hair cut off and is put in a tin shed. If one looks carefully, one can tell that the child inside the tin room is actually a boy with a slight mustache. (00:26:35)
Revealing mistake: When Moodoo is tracking the girls, he picks up a branch and examines it. Look at his horse in the background - it's bending over as though looking for food, but it doesn't move an inch, revealing it to be a backdrop.
Chosen answer: The Tracker didn't actually want to catch the girls, he only had the job so he could stay close to his daughter in Moore River. He has a lot of admiration for Molly's cleverness, how she covers the tracks and so deliberatly misses the tracks to give the girls a chance.