Disclaimer: It turns out that his wall charger was wired incorrectly, so mains voltage was wired to the ground of the vehicle, and well the chassis is the vehicle’s ground, hence the voltage. Source. Thanks @WalkingOnEggshells@beehaw.org for the correction.
You can electrify the body and wheels of a car via the charging port, the one part that consumers should be safe to assume is fully insulated against reversed wiring, surges, etc.