Being a metalhead myself, this sounds like an interesting story, but I have to say fictionalized documentaries are not my preferred genre exactly for the reason of blurring the line between fact and fiction.. Especially when they portray serious events such as this one. I am curious to see the movie!
!1UP
Of course it is pure fiction, it does not mean that this movie shows 100% of what really happened, but it serves to entertain you.