I'm not sure I agree with you. The movie was written, directed and produced by show business professionals and had many professional actors in it. It just wasn't produced by a major movie studio. It was an independant film with the copywright holders sanction attached to it.
Besides I wonder if Keith would argue this if Stephen King were nominated for a novel he wrote that he had printed by a vanity publisher. Would he argue that it wasn't a professional novel just because it wasn't published by any of the major book companies?