Factual error: When Peevey gets stuck in the truck, Cliff fires up the rocket pack and simply pushes it clear. If the rocket pack can push out enough thrust to move a 2 1/2 ton truck, Cliff's body can't take that kind of stress. He stretches his arms out, starts pushing, and sets off the rocket, putting himself between the truck and an accelerating rocket demonstrably capable of moving it. The truck is stationary so has 2 1/2 tons of inertia. The rocket instantly accelerates it to an appreciable speed. Human arms cannot take that kind of stress. He's going to be crushed.