According to IMDB:

"The Movie playing on the small TV set that Kook's (played by Actor Peter Dobson) watching in his trailer, is actually Peter Dobson's award-winning short film, WHITE MULE. The production had no money to find any footage, so they opted to use Peter's Movie. "

http://www.imdb.com/title/tt3722052/trivia?ref_=tt_trv_trv