Factual error: In the final scene where the gas grill blows up, the arm that falls to the table in front of the mother is not from a teenager - it is nearly twice as large as the young man's arms (as previously seen in multiple scenes). Some people say it's a leg, but if that's so it's a bit odd having fingers on the right side of it... (01:25:11)
Factual error: When Kat is driving the survivors and they crash into the field, they slow to a stop while spinning - there is no way the car would travel backwards with the speed that it appears to in the next shot.
Factual error: When the surviving state trooper is searching the police database for Alex Browning the search results pop up in a new window although the box that says "Open in new window" is unchecked.
Factual error: The truck flatbed that is carrying the logs has a fuel tank attached to its underside. Flatbed trailers do not have these. (It's a fuel tank for enclosed refrigerated trailers.)
Factual error: When Timmy (the kid who gets crushed by the glass slab) is at the dentist, the tube on the water tank comes off and water spurts out. That tube is the water intake, so if it were to break of it would be sucking in air, it would not be spurting water out.
Factual error: In the scene with the defibrillator it shows on the trace that her heart rhythm is asystole. Defibrillators only work with shockable rhythms i.e. VF (ventricular fibrilation) or pulseless VT (ventricular tachycardia). Using one on an asystolic patient would have no effect at all.
Factual error: The cop has a badge, but New York State Police don't wear badges. (There is an official badge, they just don't wear it on their uniform).
Chosen answer: Eugene's death had no clues I know of, but Clear and Rory's did, Rory's clue was with Nora's. The trophy's shadow is segmented, giving it a divided look, Rory ends up divided to pieces by the barbed fence. As for Clear, Bludworth hints at it with his comment "such fire you have now".