Getting fireworks on Christmas Eve - or at almost any time - in Southern California would not only be incredibly difficult to do, it would be illegal. Without a license, it's unlikely he would be able to purchase the types of fireworks displayed at the end. And even "safe and sane" fireworks that can be purchased by the general public, can only be sold a few days before and after July 4th.
Luke broke his arm on his birthday (November 28th) a broken arm takes at least six weeks to heal, so his arm should still be in a cast at Christmas.
Jay only delivered two Christmas Eve presents to Cam and Mitchell, he forgot to get one for Lily.