Yes, together with mass-energy equivalency it would form a coherent argument, and then also a correct one - but the thing is that if incomplete, it still might sound funky enough to you to research it if you care.
I think it helps that it's a very narrow field to look at, compared to fuzzy and big-picture view of social studies, for example. So much room to be confidently wrong... And sadly I can't think of a solution, LLMs or not.
He was right that it violates conservation of mass. He was completely wrong that it violated it by adding 2 atomic mass units when hydrogen fuses.
In reality heavier isotopes of hydrogen fuse, conserving the total number of nucleons, but the resulting hydrogen has a lower rest mass than the parent particles. The extra mass is released as energy and the total energy is conserved.
By his logic the system either violated energy conservation (by creating nucleons while releasing energy) or was endothermic (creating nucleons from the surrounding energy).
There actually is a law of conservation of mass (it's the same law, because mass is energy) and it only appears violated if you forget about the particles that are zooming away at the speed of light. Of course the mass of a system changes if mass can flow in and out.
When you put a photon in a stationary box, the "relativistic mass" of the photon becomes part of the "rest mass" of the photon-box system. You can't ignore it.
I think it helps that it's a very narrow field to look at, compared to fuzzy and big-picture view of social studies, for example. So much room to be confidently wrong... And sadly I can't think of a solution, LLMs or not.