Revealing mistake: The marijuana plants being grown in the film are obviously not real. The plants in the film have very plastic looking leaves with no serrated edges like real marijuana.
Revealing mistake: When Dog's gang begins getting in the van after the robbery, John is sitting in the back of the van with the barely conscious traffic warden. The actor sees the others start getting into the van, so he lifts the traffic warden's head up from the floor and just about starts his dialog. He then seems to realise that he's jumping the gun and quickly pushes the traffic wardens head back down. A few seconds later the whole gang is in the van, so the guy in the back picks the traffic warden's head back up and starts his dialog like he was supposed to.