From my understanding of RSA UFOs, that is not true as Gnosis only received N and there is no way for him to figure out the factorization of N, which is two large unfactorable numbers P and Q. By combining multiple RSA UFOs, I think Anoncoin is using 13, it ensures that the person that solved one of the UFOs in the distributed computing project cannot know the final accumulator, and Gnosis can't either since he doesn't know the factorization of the 13 RSA UFOs. It makes sense to me how it works and you are incorrect in saying Gnosis knows the factorization of N, as without a LOT of computing power it is impossible for him to know that.

The only worry I have about the RSA UFO project is that possibly someone already knows the factorization of N (IE. The government), or someone will later find it out with faster processors in the future. I am not sure if this is a realistic thing to be worried about though, as the only thing I know about this stuff is from doing research on ZeroCoin/Zerocash/Anoncoin. I will try to reach out to the Zerocash Devs to get their opinion on the RSA UFO project, as I would trust their opinion over a random poster on these forums (no offense).