Before John Morgan is captured in the lake, an Indian runs into the camp wearing Morgan's robe around his middle. When the Indians capture Morgan and drag him from the lake, his robe can be seen on the shoreline.
After Morgan has shot the bird, he puts his rifle on the ground to clean it. Then leans upon it. In the next shot he holds it in his two hands removed from the ground. In the next shot the rifle is on the ground again.
Morgan lives with his adopted tribe at least a year, and yet his hair doesn't seem to grow more than an inch at most.
Based on the interior scenes of the sun ritual the tent where it takes place would have to be at least twice if not three times as large as the rest of the tribe's lodgings. Yet this tent is never seen anywhere around the camp in outdoor shots.
When the band of Indians first stops after capturing Morgan, he is seen standing at the horses enter the clearing. In the next scene, he is on the ground, as he had been after falling in the previous scene.
At 39:42 two Indians cast shadows in opposite directions: on the ground and on the tepee, simultaneously.
Throughout the film the actress playing Running Deer can be seen with medium long, nicely manicured fingernails.
When the Indian child fires an arrow at the two wandering enemy tribe members, the arrow tip has a black rubber sucker on it.