After Taft runs MacGruder into the helicopter's tail rotor, Liles drives by and sees the body, which doesn't appear to have suffered a grave head injury. MacGruder is lying on his stomach with his hands over his head and no blood visible.
When MacGruder tortured Hugh in the cabin, blood was everywhere. When Forest goes back to Hugh's cabin, there is not a drop of blood anywhere.
Hugh steps in front of his computer to hide the vital floppy disk, then immediately leaves. Later, the disk is hidden in the closet behind the computer.
When Forrest enters Hugh's cabin, the gun cabinet is briefly visible, with a bolt action rifle on the left, a single barrel shotgun in the middle, and another rifle on the right. When they come down from upstairs, the two rifles have swapped places, and the shotgun is now double-barreled. The two boxes of shells have moved from beside the rifle butt in the bottom right corner, to a shelf near the top of the cabinet.
Shortly after blowing up the mercenaries' helicopter, Forrest rummages in a bag while wearing gloves. In the following shot, the gloves are gone.
When Steven Seagal hurls a villain through a pane of glass, a microphone and operator are very visible to the left of the shot.