Revealing mistake: During the helicopter flyover several 'corpses' are seen lying in a depression in the dust where they fell after dying (imagine a 'snow angel' to see what I mean). However, there are no footprints leading up to any of them. Any soil loose and powdery enough to form a depression when a body lands in it would hold footprints. And if there was a strong enough wind to erase footprints it would have piled some of the dust up against one or more sides of the body.
Suggested correction: Unless you are suggesting that the production crew dropped the actors into place from a helicopter, the configuration you see is obviously possible in real life. The actors playing the corpses walked to their positions for filming.
Or more dust was laid down by the production crew once the actors were in place, presumably to cover the crew tracks which would have shown a lot of activity, and had the side effect of covering the actors' prints too. They either didn't realise or didn't think it was worth recreating the steps.
