Other mistake: When Lucy asks for an extra piece of candy for her brother during the Trick or Treat scene, her right hand has five fingers when she holds it up, but her left hand only has four fingers.
Other mistake: When the kids leave Linus standing alone in the pumpkin patch, Sally decides to rush back to Linus, and when Linus explains that she'll see the Great Pumpkin with her own eyes, Sally's left arm is blue, the same color as her dress, then instantly changes to the normal flesh color within the same shot. (00:11:20)Super Grover
Other mistake: When Snoopy starts sneaking through the pumpkin patch, Sally is standing with her arms crossed and Sally's hand is painted blue while talking to Linus. (00:20:35)