You can't assign probability to human motivations. You're making this enormous assumption about human motivation in the last three paragraphs that has nothing to do with your "probability proof".
Even assuming you're right, why would they put in giant red text "DON'T USE THIS FOR CRYPTOGRAPHY" at the top, if their goal was to get you to use it for cryptography?
Further, I reviewed the architecture in the write-up.
If they wanted a random beacon that was not backdoored, they would xor it with samples from a lava lamp or something simple and unpredictable and point a web cam at it that anyone can see. As explained, this cannot reduce the randomness.
They would not carefully design an architecture that is possible to backdoor, which is what we are reading about.
As for the reason why they say it should not be used in cryptography, I addressed these in my original comment.
In my estimation the chances that the government can predict the output of this random beacon are 200:1 in favor.
Even assuming you're right, why would they put in giant red text "DON'T USE THIS FOR CRYPTOGRAPHY" at the top, if their goal was to get you to use it for cryptography?
Nonsense