Other mistake: When Chozen is buying vegetables from the villagers, one of the weights from the scale is knocked onto the ground. Daniel picks it up and realises that its not a real weight and breaks it in half. If Chozen wanted to cheat the villagers when he weighed their vegetables, he would need weights that were heavier than normal, not lighter plastic ones. Lighter weights would mean that Chozen would need to add far more of the light weights to make any amount of vegetables balance out, therefore he would be paying more for the vegetables than they are worth.
Other mistake: After his wife has a party at their house, Thorton Melon (Dangerfield) decides to have a swim in his pool. The camera shows Melon as he is about to dive into the pool from the edge. The camera cuts away and a much "thinner" Melon is seen doing a flip into the water. Watch carefully as the "thinner" man makes his dive. You can clearly see his hairpiece fly off the top of his head.