No, Carmack holds the burden of proof because he started the argument. His incapable program does not prove anything.

Maybe this is formulated a bit harsh, but let us respect the logic here.

One of my supervisors used to say: "Don't tell me it's impossible, tell me _you_ could not do it." A true c_nt move that ends every discussion.

Huh, by saying that something is impossible, __you__ are ending the discussion, not your professor.

No. Pointing out a flaw in an argument doesn't require proving the opposite.