Soon after Doc Hawkins is killed we see him in the background riding his ATV with the rest of the group. A huge crowd of the production crew can also be seen in this very same shot.
When Rutger Hauer's character spots the cave Mason is hiding in, it is illuminated by orange light (as if a fire was lit inside). In the next scene, inside the cave, it is lit with the blue light from a flashlight.
After dinner, Doc Hawkins offers Mason a full pack of cigarettes with a few of the cigarettes sticking out of the top of the packet holding the lid open by placing it on the table. In the next shot when Doc Hawkins pushes the packet closer to Mason the packet is half empty with no cigarettes sticking out .
After Mason jumps in the river and swims downstream, he discovers his cigarettes are still dry. This despite the fact he was completely submerged and his clothing was drenched.
When Mason fights Wolfe Sr, it's still pretty dark, but in the shot of Burns driving away there's quite a bit of light. We see one shot of Mason shouting - dark again - and then Mason too gets on an ATV - and suddenly there's a lot more light.
After they wake Mason and chase him out of the house Burns racks the pistol and fires at Mason's feet. The pistol's slide locks back indicating that it fired its last round. Burns then fire it again and the next shot you can see that the slide is still locked back, again indicating that there are no more bullets. He then fires it for a third time without reloading or racking the slide. He should have been able to only fire the first shot, the other two shots were impossible.
When Wolfe Sr. is shooting at Mason in the dark he empties the magazine of his semi-automatic. There are sounds of him pulling the trigger and the hammer falling on empty chambers as if the gun is empty but it can be seen that the slide is locked back and therefore the trigger would not be able to operate the hammer.
Near the end of the movie it states that it is "Three Days later in Seattle" and the skyline that is shown is clearly that of Philadelphia. Skyscrapers Liberty Place One and Two in Center City are shown.