> To me, the fact that illusion and hallucination are being invoked is strong evidence of handwaving being engaged in to dismiss an otherwise difficult problem. This is not a scientifically rigorous explanation and it doesn't take the other side seriously.

Yeah. IIRC, some people say the passage of time is an illusion too. It's pretty hard for me to take seriously anyone who defends their favored theory or interpretation by hand-waving away contrary but fundamental observations as illusions.