The "fog" is done by a film over the camera lens or in post-production as it obviously follows the movement of the camera.
A soldier fires four short bursts from his Thompson sub-machine gun at a door. When the door is opened, on the inside of the door there is no damage visible to the lock or the doorknob hardware.
Second Mate Wilson fires seven shots out of his six-shot revolver.
Tio tells Steve to broadcast the word "Yankee" to his friends across the border, but there is no mention of what the frequency should be before Steve starts to key in the word via Morse code.