In this case the paradox lies within having made a false statement about Omega, not about TDT. In other words, it's not a problem with the decision theory, but a problem with what we supposedly believe about Omega.

Yes, that is what I meant.

In considering this problem, I was wondering if it had to do with the directions of arrows on the causal graph, or a distinction between the relationships directly represented in the graph and those that can be derived by reasoning about the graph, but this false statement about Omega is getting in my way of investigating this.