Factual error: As part of her quest to kill John Belushi, Carrie Fisher shoots at the brothers with a flamethrower. She is earlier seen reading the manual for the "M-79 Flamethrower." The M-79 is a grenade launcher - the one Schwarzengger carries in "Terminator 2." (01:07:00)
Factual error: The Palace Hotel that The Blues Brothers do their big show in is supposed to be 106 miles up north. That would put it in Wisconsin. The flags that fly outside the hall are the Ohio state flag. (01:44:15)
Factual error: When the Blues Brothers are trying to escape the Illinois Nazis, they are on a freeway heading through a construction site. They break through several barricades, jam on the brakes, and stop just before they go off of a bridge. They slam the car into reverse and flip through the air to escape. The Illinois Nazis go over the bridge. The bridge is in Milwaukee, WI. The tall white building in the background is the US Bank building in downtown Milwaukee, WI. As the Nazis fall to earth, they fall past a building in downtown Chicago, IL before going through the street on impact. The Nazis fell from Milwaukee, WI to Chicago, IL. (02:11:00)
Factual error: Legitimate religious institutions are not subject to property taxes.
Answer: It was a double, and the "making of" documentary on the DVD shows this.
David Mercier
To be fair, John did do a lot of flips and dancing as Jake; just not all of them in the movie.