When Sharon and Sam are shopping for a Christmas tree there is a printed sign in the background that plainly says "All Trees $15". A few seconds later the same sign is now handwritten and says, "All Trees $75".
When Sam asks Sharon out for diner she has two necklaces on. Just after they part company she only has one.
When Sharon and Sam are assembling the Santa and Reindeer lawn display, you can spot the fake sponge foam layer of snow as they step onto it and wide areas of the material depress into the ground instead of the footprint-shaped impressions that real snow would create.
When Sharon and Sam make an appointment to meet for the first time, they mention a time but not a locale before they part company.