A front loader tractor supposedly full of dirt and rocks unloaded on a character, killing them under the weight. Is clearly shown completely empty in the previous shot, right before it happens.
In Sid Wisløff's flashback, where he "solves" his first case, turning in his father for moon-shining, Sid is caught drinking the last Coca Cola in the house. The bottle in the film is shown with a paper label. In the 70's, the time of the flashback, Norwegian Coke bottles had the logo painted on the bottles. They did not have paper labels.
Sid Wisløff as a kid has brown eyes, but as an adult he has blue eyes.