The recent experimental determination of the parity violating asymmetry A_{PV} in ^{48}Ca and ^{208}Pb at Jefferson Lab is important for our understanding on how neutrons and protons arrange themselves inside the atomic nucleus. To better understand the impact of these measurements, we present a rigorous theoretical investigation of A_{PV} in ^{48}Ca and ^{208}Pb and assess the associated uncertainties. We complement our study by inspecting the static electric dipole polarizability in these nuclei. The analysis is carried out within nuclear energy density functional theory with quantified input. We conclude that the simultaneous accurate description of A_{PV} in ^{48}Ca and ^{208}Pb cannot be achieved by our models that accommodate a pool of global nuclear properties, such as masses and charge radii, throughout the nuclear chart, and describe-within one standard deviation-the experimental dipole polarizabilities α_{D} in these nuclei.