  Regardless of past proposals (already disproved in experimental work by Brida
et al), the Wigner picture of Parametric Down Conversion (works by Casado et
al) can be interpreted as a local-realistic formalism, without the need to
depart from quantum mechanical predictions at any step, at least for the
relevant subset of QED-states. This involves reinterpreting the expressions for
the detection probabilities, by means of an additional mathematical
manipulation; though such manipulation seemingly provides enough freedom to
guarantee consistency with the expectable, experimentally testable behavior of
detectors, this is, in any case, irrelevant in relation to our main result, of
a purely mathematical nature. Besides, the Wigner-PDC approach opens clear room
to explain the elusive nature of a loop-hole free proof of the incompatibility
of nature with that local-realism, without the need to assume hypothetical
technological inefficiencies yet to overcome after several decades of
experimental work. In relation to this, we also address the consequences of
this framework in relation to typical Bell experiments. Additionally, we also
propose an extremely simple interpretation on that apparently awkward
"subtraction" of the average ZPF intensity at the Wigner image of the detection
process.
