Sounds like you know more about these than I do. Part of why I was curious about a tear down. I'm wondering if any corners were cut on these such as improper isolation. Naturally it could also be the car itself has a short that blew itself and the dispenser up. Maybe a rubbing wire on the car with a high resistance short that melted and bridged then tripped the MCCB temporarily disabling the charger.

Judging by the quality of automobile maintenance and manufacturing I would bet on the latter now that I think of it.