This says that the voltages can reach 380v inside the case of a computer, but really, in a modern computer only the inside of the PSU would ever have anything over 12v. Did he take the case off his power supply too?
The only exception I can see would be if he has one of those cases where there’s a cable running from the external power port and the power supply (Like my Antec Aria and Antec 2u20 cases, though they both have electrical tape covering the posts in the connector) and then it wouldn’t be more than 220v in china. 220v can kill you though…
The other alternative is that they’re using substandard computer parts in china where the power supply innards are exposed.