Factual error: The frequency which is used to attract the dragon fly is said to be "sub-sonic" and therefore can't be heard by humans, but the exact frequency is stated to be 38.2 Hz. This is well above 20 Hz, the lowest frequency an average human can hear.
Factual error: During the switching of scenes, when visiting where Mike 1st began, it shows a marathon gas station in the background. There are no marathon gas stations West of the Mississippi river.
Factual error: Karen says she doesn't want to divorce Jody because he'll take half her life insurance payout in the divorce, but life insurance (as well as other inheritances) are not considered marital property and don't usually get divided in a divorce.