Other mistake: Leatherface attacks the Mercedes. The pick up is driving backwards, the Mercedes forwards. The Mercedes should easily be able to outpace the pickup.
Continuity mistake: At the radio station, Leatherface cuts into the tube with the beer cans on ice. In slow motion, the chain comes off the chainsaw. After the cut, the chain is back on.
Revealing mistake: Leatherface attacks the Mercedes. The pick up is driving backwards without the reversing lights coming on. Most likely a reversed shot.