If anything comes of this, it could create a loop that would consume the world!
James Randi issues a challenge to anyone who can identify the mystery target.
Someone (challenger1) believes they can identify the target and instead of accepting the challenge, challenges Randi to undertake the challenge for entertainment.
Someone (challenger2) spots that marketing ploy, and challenges the challenger to take the initial challenge.
The challenger1 challenges challenger2 to force Randi to under take his (challenger1)'s challenge while refusing to just take Randi's challenge.
Someone (challenger3) challenges challenger1 to take either Randi's challenge or challenger2's challenge.
Challenger1 challenges challenger3 to .....
and so on....
There's no evidence that I have seen that Jim Callahan has taken any steps to directly contact James Randi, and ensure that he is aware of this challenge. I suspect that if he did, Randi would state that agreement to do this would be under the terms of Randi's challenge, but that if the two fit together, there's no reason for it not to go ahead. As long as the terms of Randi's challenge are met, I can't see why marketing it in this format should be an issue for Randi (apart from a possible desire to remove the unnecessary 'flim-flam').
However, to issue a challenge to anybody, and not make sure personally that they are aware of its existence, seems to me to be the height of rudeness, and also, quite telling of how confident a person is in succeeding.