Ahhh, now this thread is starting to get interesting...
I see what you're getting at, but I'm afraid you're wrong. Let's forget unicorns, dragons, and even elves for a minute. In most cases, when you state something with a positive sentence, you can say exactly the same thing with a negative sentence, and 5555 and you are arguing that the actual wording determines who gets to prove what he or she says, which isn't logical at all.
Here is one example: should a lawyer say "My client is innocent", then according to you, he's got to prove that what he says is right. Fair enough. But should he say "My client isn't guilty" (which means exactly the same thing), then the burden of proof would fall on the prosecution. In real life, innocent until proven guilty or guilty until proven innocent depends on your judiciary system, not on the opening statement at the trial.
Here's another one: it is widely accepted as truth that the Americans landed on the moon in 1969. However, conspiracy theorists like to say that this is false. In a conversation between two different-minded people on this issue, one saying "The Americans landed on the moon" and the other saying "They never did", who do you think is going to have to prove what he says? That's right, the one who stated that the Americans *didn't* land on the moon (ie negative), because he's going against the perceived notion of "truth". Doing otherwise would be engaging in sophistries all day long, and you could then "prove" (ala 5555) that nothing is certain and that nothing exists. (For example, "The Americans landed on the moon in 1969." "The burden of proof is on you because you stated something in a positive way, so prove it." "Here are the photographs, the recordings, etc." "Prove they haven't been doctored." And as he can do that ad vitam aeternam, you just won't get anywhere in the end.)
Back to the matter at hand, we're not arguing on the point he brought up. I never said "reliable sources" cared about what I wrote (I couldn't care less whether they did or not, tbh). However, he claimed that they don't care. I don't have a problem with that, but he brought that up, he's got to back it up with facts. Otherwise, he's just talking out of his backside.