Yes, that is exactly what the problem was, though it got lost in the drama.
The car has a protection mechanism to prevent the battery from freezing, and when left over night in the cold without a charger, it will actually run an auxiliary heater to keep the battery warm enough.
The reviewer expected the charge to be the same in the morning, so he called their technical support when it was so low. They didn't explain that the charge can substantially decrease overnight when parked in the cold, because it automatically runs a heater for the battery. Instead they suggested that it was an erroneous reading, and that it would correct once the battery heated up.
It wasn't really a design flaw so much as a mistake from technical support exacerbated by an overbearing response attacking a journalist for not being omniscient.
