I haven't said anything about the math being wrong.

The model that Fyookball proposes doesn't properly describe the system in question. Thus, it's not interesting what he's calculating.

Let's assume we were talking about a new type of airplane. A disputant models the airplane as an omnibus, does some calculations and concludes that the airplane can't fly. Would you bother discussing the calculations in detail or point out that the omnibus is not a good model for the subject of our discussion?