Does that take anything away from the argument?
I suppose it's additionally trying to imply something else, like "due to a pattern of researchers being unable to discover discoveries before they discover them, AGI is just around the corner".
it's a different thing to say "it's mathematically impossible"
so if it turns out it is possible, what then? was math broken? or the researcher an idiot who either doesnt know math, or is just bullshitting non-existing proofs?
(I don't know the details of what happened, it could be either or neither of the things you said.)