Other mistake: After the turkeys start attacking in "The Running of the Turkeys", Mr. Fishoder and his brother start running. In that clip a Turkey pops out the side of a guy's head. Look in the mid lower right side. Looks like a design error. Pretty big error, no slow down needed to see it. (00:05:20)
Other mistake: When Bob and Louise are trying get the theater for the Hawk and Chick film festival, the employee tells them the last showing on Saturday at 11 pm. However, after the film is shown, Bob makes a remark about the time and asks if it is a school night. Gene says yes and he has a big test the next day. If the film festival happened on Saturday, then the next day would be Sunday. There would not be school.