Gaffes

Christine places the locket on the tree and yet when she turns to kiss Jason it is seen back around her neck.

When Jason draws Christine's attention to the celestial "big dipper," he remarks that the star on the end of the "handle" is the North Star. However, that star is not part of the big dipper, and is actually located above the opposite end (the bowl) of the dipper.

The North Star, or Polaris, is the last star in the handle of the Little Dipper (Ursa Minor). It is not very bright, so the two stars on the far end of the dipper portion of the easily visible Big Dipper are used for direction, as they "point" towards it.

Christine would not have been able to open Judy's car door, which would have been auto-locked from the inside.

Someone pointed out that Jason made an error about the North Star but he actually did say Little Dipper, not Big Dipper so his description of the location of the North Star was correct. It was watched with closed captioning to be sure.

Christine works in a Bakery Shop around food. Her hair should be tied up and away from her face. In the Food Industry, it's a big no-no to have long hair not secured so hair doesn't end up in the food.

When the kids are opening their gifts, the label on the doll says "From Great Grandma", but the doll was delivered before they found out who the great-grandmother is.

Betty would have had pictures of Christine's parents, like from prom.