[vreihen16]

I doubt that the GFCI will protect you from a plug pin that gets hot due to an incomplete/loose connection, like the above appears to be. It does not act like a current-limiting circuit breaker in the event of a short.

I don't have the schematics of the OUC cable, but do know that the OpenEVSE hardware includes internal GFCI detection by design. I'm pretty sure that it is required in EVSE's by UL or somebody, so it may be worth verifying and also doing some research to see if having double GFCI causes any other problems.....