The issue is not the LEAF, but the EVSE's behavior, because it could be used with any J1772 vehicle.
Perhaps Panasonic (and Nissan?) felt the diode-test was optional in the Standard, and they wanted it to work with "ventilation-required" vehicles?
There is no "For Use Only with the Nissan LEAF" warning on it, nor a
"Caution: This EVSE does Not Comply with all J1772 Safety Standards".
Maybe such warnings appear in the User Manual?
It is nicely compact, but it easily could have been designed to be fully J1772 compliant.
Perhaps this is ONE of the reasons that Nissan so strongly encourages installation and use of another (L2) EVSE?
Perhaps Nissan did not fully anticipate the many owners who intend to use the included L1 EVSE on a daily basis, as their "normal" means of charging?