By analyzing the decay of a compound system into two praticles, we show that measurements on particle 1 will define with an arbitrary degree of precision the coordinate and momenta of particle 2 at times large compared with the lifetime of the compound system, i.e., when the two particles no longer interact. Thus we have an example of the Einstein–Podolsky–Rosen argument in which all the requirements of quantum mechanics are met. Criticism of the point of view they present should then center on their epistemological position (such as their definition of physical reality) rather than on their use of the quantum‐mechanical formalism.