This reminds me of a Maranatha video I saw in college about backmasking. Their premise was that supernatural forces were to blame for the messages supposedly present on some music played backwards.
Here was the sum total of their stellar reasoning for eliminating other possibilities:
--- a deliberate act of the artists: "it's too hard. if you don't believe us, try it yourself."
--- total random chance: "if that's the case, then we should be just as likely to hear positive or neutral messages like 'worship Jesus' or 'eat toast' as we are satanic messages."
So you see, it just HAD to be supernatural.
Of course, even when they told you in advance what it was you were going to hear, it just didn't come through when they played the backwards music. Were you aware that one of Cheap Trick's songs played backwards says "Satan Holds The Key to the Lock"? Neither did I. Only despite the video's claims, it really doesn't.
There was, however, one exception: "Another One Rights The Bus" played backwards really DOES sound like "Start to Smoke Marijuana"---at least if the speaker has marbles in his mouth :)
I meant "Another One Bites The Dust", of course. I managed to mix up Weird Al Yankovic and goodness knows what else there.
i don't remember that one, but seems similar.