When Sheriff Tom Sworn drops off Christina Wendall and his two daughters Alyssa and Alexa Sworn at the dance, two girls dressed as a sailor and a gypsy are seen walking past (behind them) twice going in the same direction. You can see them (then their shadows) go past the boy dressed as a skeleton (with a tin foil hat) and up the stairs. Then the sailor girl is seen approaching the skeleton boy as if she had just walked past the other girls.
Shelley has normal human fingers sticking out from the bandages on her hands. In later episodes her fingers are just charred bits of bone.
On a classroom door, chemistry and 101 are backwards.