The lieutenant and Fletcher approach the house and are seen from behind standing on a well-tended lawn. The front shot shows them standing on uneven ground with tall straggly weeds.
When Mac looks from the raft to the house, there are no people in front of it. However. the close shot shows four guards.
At the 31:00 mark, Sidney brings some water in his cupped hands for The Girl to drink. The next shot after she has finished drinking shows Sidney's hands to be completely dry.
The shots of the dead girl show her either with her face three-quarter turned to the ground (close shot) or with her face looking straight out to the side (long shot). This may be deliberate due to the surreal nature of the scene, namely the mental state of her killer.
Our heroes steal a plane from an enemy military base. However the plane (a Luscombe 8) is clearly a civilian airplane with no military markings whatsoever. It is unlikely an obvious civilian aircraft like this would be on a military base.