 The unreasonableness to which EPR allude in making “the reality [on the second system] depend upon the process of measurement carried out on the first system, which does not in any way disturb the second system” is just the unreasonableness that would be involved in renouncing locality understood as above. For it is locality that enables one to overcome the incompatibility of position and momentum measurements of Albert’s system by requiring their joint consequences for Niels’ system to be incorporated in a single, stable reality there. If we recall  Einstein’s acknowledgment to Ehrenfest  that getting simultaneous position and momentum was “not logically necessary”, we can see how EPR respond by making it become necessary once locality is assumed.