Points like this seem to be rediscovered every ten years or so; I am never sure what to make of them. What ever happened to Alain Lewis?
As Cowen surely knows, stuff like this happened to Alain Lewis as his research was derailed by mental problems, permitting much of the economics profession to ignore his work and dismiss broadly similar results as crackpot.
So, really, that was about as subtle and considered an argumentative response as making a circular finger motion (loony!) around your ears.