Continuity mistake: As the guys sit down for a beer and start talking, the viewing angle is from behind the one listening. As they switch to the other one who's about to say something the two bottles of beer magically turn around so you can always read the front label, no matter from which side the scene is shot.
Continuity mistake: When Charlie Sheen and Emilio Estevez are on their way to the toxic waste dump, each of them are hanging off of separate doors on the toxic waste truck. When one of them gets stuck the other helps him and both swing onto the flatbed. When they are hanging, the yellow barrels are lined until the end of the truck, but when they swing in and land in the truck there is 3 feet of clearance.