A local, deterministic, and realistic model within a Friedmann-Robertson-Walker spacetime with constant spatial curvature is presented which describes simultaneous measurements of the spins of two fermions emerging in a singlet state from the decay of a spinless boson. Exact agreement with the probabilistic predictions of quantum theory is achieved in the model without data rejection, remote contextuality, superdeterminism, or backward causation. An event-by-event numerical simulation of the model is presented, which confirms our analytical results with the accuracy of 4 in (...) 10,000 parts. (shrink)