Continuity mistake: When the they first show the Evil Snow-Plough Man, he's chasing kids and they run off to the left side of the road as proven when the kid's sled gets crushed. However, once he's past, they all pop up from a mound of snow on the right side of the road.
Continuity mistake: When the wife gets hit with the snowball thrown by her kid, she throws her phone. If you look in the background right after that you can see the phone in plain sight laying in the snow between her and the house. A fer scenes later however it has jumped to under the tree.