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.
Trivia: Location filming in Calgary's Mount Royal neighbourhood was disrupted when two bank robbers crashed their getaway car into the set. They hit a fake police van and were soon surrounded by over a dozen men and women in uniform. They surrendered only to find out later that they had surrendered to extras. (The real police showed up soon afterwards.)