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.
Chosen answer: If you are playing blind, you obviously aren't allowed to see your cards, nor exchange any cards. So if I'm playing open, I've seen my cards (and only me) and after the first round of betting I can exchange some or all of my cards. Statistically I'm now going to have a much greater chance of having a better hand than the blind man. Both players know who's likely to have the best hand, so it's a very brave gambler that plays blind for more than a couple of rounds. Imagine betting hundreds or thousands of pounds on cards that you haven't seen versus a hand that your opponent has managed look at and change. The rule an open man can't see a blind man tries to even up the odds, and make the game more interesting. It's literal seeing, rather than poker terminology.
They are playing 3 card brag. Nobody can exchange cards regardless of whether they see or not.