Just out of curiosity, what was this challenge?
Here's a monster thread about it: http://www.apollohoax.net/forum/index.php?topic=269.0
I read all 1,681 posts, and one thing strikes me.
I'm surprised that no one here has a flesh-eating lawyer friend, who could have filed a lawsuit against Björkman for fraud, failure to pay, or any one of a few more civil charges.
It seems to me, that if the conditions of the challenge were met (and it can be shown that they were) and that the challenger read those posts (and it can) and that he responded to other posts after those (and he did) with the intent to change the conditions of the challenge) then a legitimate legal case could be made that Björkman would have to pay up, because the original challenge, and the revised challenges were satisfied, and that intentional evasion to avoid payment was undertaken by Björkman. It was noted more than once in the thread that he had committed fraud by doing so, and it makes me wonder why no one at least indicated that they were going to be filing such a suit. It would have been interesting to watch Björkman squirm, knowing that he would have to acknowledge his ignoring the responses, in a courtroom.
Of course, I understand that nobody really would have done this, because it simply wouldn't be worth the effort, but at the very least, a realistic threat of litigation might have forced him to acknowledge the correct responses in some way. Wishful thinking on my part, I suppose, but if I had been around then, I likely would have threatened such litigation. I know a couple of flesh-eating lawyers...