Could they have stolen the story? Yes. But they could have equally had a similar experience, it's not that implausible. I've known people that have nose bleeds like that, it's not some incredibly rare condition, and saying hail Satan is the kind of thing tons of edgy kids/teens would do.
Things can happen more than once.
Or just do what other people breaking the law do and release it entirely anonymously via torrent, once it's out there it's out there.
Don't even have a website or explain anything, just dump it on pirate Bay and let word of mouth do the rest.