Continuity mistake: During the mall chase, a semi-profile shot shows the squad car roll onto its roof and slide with a large panel of orange signage pinned under the roof. Camera cuts to a view of the officers inside the squad car, and there is no signage nor any other debris pinned under the car's roof. Camera cuts back, and the signage is again pinned under roof. Camera cuts back to frontal view, and the signage is gone again.
Continuity mistake: The woman in the car trying to shoot Jake has a couple of errors. First, she gets six shots out of a four barrel weapon without reloading. Second, she goes from having the weapon out of the window, to no weapon and driving in one second, where it took at least five or six seconds to get it out and aim it.
Character mistake: When Elwood tells his boss he is going to quit, his boss tells him he will call payroll and have them get his severance pay ready. While employees who resign do have final pay prepared (pro-rated pay, vacation pay, time owed in lieu, etc.) it would never be classified as "severance pay" if the employee resigned on their own accord. Severance pay is classified for employees who are terminated without cause, meaning no fault of their own. (00:43:10)
Continuity mistake: When the Blues Brothers are paying the assessment in the Cook County Assessor's Office, the area behind the assessor has a desk and is not very wide. In the shot where the camera has panned out, it shows a much larger area behind the assessor. Additionally, how did all of the emergency services personnel get in the room without anyone in the shot seeing or hearing them. When it cuts to this scene, the Blues Brothers look surprised, but they should have easily seen and heard this. (02:18:44)
Continuity mistake: Throughout the "Everybody Needs Somebody" song number, pay attention to the band member in the background smoking a pipe. More specifically, watch the smoke coming out of his pipe. Sometimes it's consistent from shot to shot, but at other times, it changes completely. (Ex. When Jake sings "When my soul's on fire," all of the smoke disappears between cuts).
Continuity mistake: When the Blues Brothers first go into the tax building in Chicago, the building has gold numbers above the door that they are blocking from the inside that read 118. When the rest of the cops and a firetruck pass by, we now see the numbers are black and not even the same shape as the gold ones.