Continuity mistake: The newspaper on the girl's face appears and disappears.
Continuity mistake: Throughout the movie, the van of teens passes the Blair Meat Co. and the gas station, which are on the right side of the road. Then at the end of the movie when Erin flags down a trucker, he is heading the same direction except the meat company is now on the left side of the road. The gas station, however, is still on the right side. If they were on the same side of the street before, how could this be? They don't show either driver making any turns.
Answer: He wasn't a real sheriff - in Texas Chainsaw Massacre: The Beginning it shows him shoot the sheriff and take his clothes and car.