As the Indians are getting ready to slay the cow that Custer gave to them, a spear lands at their feet. The spear traveled across the screen from left to right, however the Indians that threw the spear arrived on the screen coming from top to bottom. You can see the spear in the ground is not facing the same direction as crazy horse when he arrives.
After the trail boss frantically yells out that the herd is about to stampede, the camera switches to the herd which is calmly just standing around doing nothing.