  We present the joint NuSTAR and XMM-Newton spectral analysis in the 0.6-70
keV band of three candidate Compton thick (CT-) AGN selected in the 100-month
Swift-BAT catalog. These objects were previously classified as CT-AGNs based on
low quality Swift-XRT and Swift-BAT data, and had soft photon indices
(Gamma>2.2) that suggested a potential overestimation of the line of sight
column density. Thanks to the high-quality NuSTAR and XMM-Newton data we were
able to determine that in all three objects the photon index was significantly
overestimated, and two out of three sources are reclassified from CT to Compton
thin, confirming a previously observed trend, i.e., that a significant fraction
of BAT-selected, candidate CT-AGNs with poor soft X-ray data are reclassified
as Compton thin when the NuSTAR data are added to the fit. Finally, thanks to
both the good XMM-Newton spatial resolution and the high NuSTAR and XMM-Newton
spectral quality, we found that the third object in our sample was associated
to the wrong counterpart: the correct one, 2MASX J10331570+5252182, has
redshift z=0.14036, which makes it one of the very few candidate CT-AGNs in the
100-month BAT catalog detected at z>0.1, and a rare CT quasar.
