Audio problem: As Shelton is about to drive away from City Hall, we see him operate a lever on the steering column of the van and we hear the familiar sounds of a transmission shifter clunking through a few settings into "Drive". The problem is that he used the lever on the left side of the column, which is the turn signal lever. The transmission shift lever is on the right side of the column. In reality, Butler used his left turn signal before steering left into the travel lane, and the sound editors added the shifter sound to try and cover the fact he's never actually seen putting the van into gear in the scene. (01:31:50)
Audio problem: When Nick and the others are flying in a helicopter to find the buried lawyer, not only does the registration number of the helicopter change, but the model is a Bell 206 L-4. As it flies along, you hear the sound of the chopper going by. The sound of the helicopter dubbed in is of an American Eurocopter aircraft with a Fenestron instead of a tail rotor. These two aircraft have a completely different sound.