Deliberate mistake: When Alex is in the cabin opening the can the pull tab is already lifted up making it easier to open because he is wearing gloves. It was already up when he took the wrapper off.
Deliberate mistake: In chapter 15 "Bad Service" as Kim drives away and almost hits the kids which are supposed to represent the "Burkittsville 7", count them. There are three girls and four boys. Rustin Parr kidnapped 8 kids; 4 boys and 4 girls. Kyle Brody survived so the Burkittsville 7 should be 4 girls and 3 boys.