One of the posts seen in the #EvacSelfie bit was from "Ash Campbell" - a mashup of Ash Williams/ Bruce Campbell from the Evil Dead films.
The film closes with a dedication to Ryan McHenry - McHenry, who sadly passed away in 2015, wrote and directed the short film Zombie Musical (2011) from which this feature film was adapted.
The movie was planned to have a full musical opening scene featuring a drunk Santa stumbling though the town center while the people around him sung "What a Time to be Alive". This scene would also feature several minor characters before they are infected, however the scene was canceled during shooting due to poor weather conditions.
This movie has 3 versions: the USA cut, which is 93 minutes long, the UK/International Cut, which is 98 minutes, and the Festival Cut, which is 108 minutes.
During the scene when Lisa sings her song at the school's Christmas concert, the man seen playing keyboard is Tommy Reilly, who co-wrote the music for the film.