When in hospital the medication on the table besides Maj Grigsby's bed moves from shot to shot.
Grigsby's team are seen walking along high ridge lines. No soldiers would expose themselves like that. They are easily seen and would make good targets for any opposition snipers.
Jackson's clothes are totally inappropriate for the incursion to find Thompson. He is wearing blue denim jeans and jacket. No mercenary would wear denim as it would restrict movement, be too hot for the conditions, and its blue colour would be easy to see. Similarly, the bright red cap would stand out at a distance and be easy to track from a distance.
On the second attempt to find Thompson, three of the team are carrying packs into the jungle, but Grigsby is not. Even though he is the leader, he would need to carry a pack with ammunition, food, water, etc.
When carrying Grigsby on the stretcher, his team are no longer wearing their packs. Even with difficulty of carrying a wounded man, the team would still need packs to carry supplies, as their journey would take more than a day.