Factual error: The sheriff mentions that they don't have a license plate on the front of their vehicle, but according to the aliens' map device, they're located in Michigan, where a front plate is not required.
Factual error: When the kids are putting firecrackers in the duct system, we see them flying around the aliens exploding. However the fireworks that were used were not the type with propellants on them and therefore would not fly around.