During his escape, Mike Danton throws hand grenades and reloads his rifle grenade launcher several times, despite never being seen collecting or carrying any grenades.
About a second elapses between shots from the tank's main gun. Main guns of U.S. tanks cannot be reloaded this fast.
The rocks Mike Danton pushes down the hillside are unrealistically square and obviously bounce like foam props.
U.S. military hand grenades have a spring-loaded lever that pops up to arm the weapon after the user pulls the pin and releases it; Cooper obviously recognizes this when he booby-traps the goon's body. However, the levers on the prop grenades never pop up, as easily seen in several closeups.
During the final chase, Col. Hogan fires his 6-shot revolver about a dozen times without pausing to reload.
The helicopter flies much faster than would be necessary to keep up with a single running man.
Throughout the film, it is obvious that the explosions are created by low-powered stunt pyrotechnics, with stuntmen feigning survival or death as the script demands.