  An experiment has recently been performed to demonstrate quantum nonlocality
by establishing contextuality in one of a pair of photons encoding four qubits;
however, low detection efficiencies and use of the fair-sampling hypothesis
leave these results open to possible criticism due to the detection loophole.
In this Letter, a physically motivated local hidden-variable model is
considered as a possible mechanism for explaining the experimentally observed
results. The model, though not intrinsically contextual, acquires this quality
upon post-selection of coincident detections.
