Making Mistakes Saves the Single Observer’s World of the Extended Wigner’s Friend Experiment

The Extended Wigner’s Friend thought experiment, comprising a quantum system containing an agent who draws conclusions upon observing the outcome of measurement state prepared in two nonorthogonal versions by another agent, led its authors to conclude that theory cannot consistently describe use itself. It has also been proposed this experiment is equivalent entangled (Bell-type) experiments. argued paper assumption freedom choice first friend regarding how prepare one available invalidates such equivalence.