When the six boys are being beaten into the police van, a camera man and assistant on the left of screen are visible for a couple of seconds.
When MCA throws a bin through the store window (at around 30 mins) the explosives that break the glass go off before the bin is near it.
When the group enters the café, the camera and camera operator are reflected in the window on the right side of the screen.
When the dance-off is about to start and also on several occasions during the dance-off, the shadows of the camera, camera operator and boom mic are visible in the lower left corner of the screen.
The three future Beastie Boys arrive in a 1981 Delorean DMC-12. The Delorean is a two-seater car and therefore the only way to (uncomfortably) transport three people is for the third to sit on the passenger's lap, but we can see as the camera pans past the car that there is only one person in each of the two seats.