Or maybe their laptop got exposed to some nasty levels of radiation.
[^1]: https://www.apple.com/shop/product/MK122LL/A/power-adapter-e...
Your laptop's body is normally connected to ground and both power supply lines are also connected to it via two capaciators. No actual current is driven through it but it does have an effective voltage of ~110V on it unless it is actually grounded. You can feel that but it should be harmless.
This applies to most electric appliances.
They have the hardware to be grounded (the metal T stub on which you attach the local plug), but they don’t come with the extended wire by default which has the grounding pin for the outlet.
In actuality, the reason you feel the tingle is because the case is effectively grounded to the neutral pin. The three phases are joined together at the transformer to create a cheap neutral, but because the load on all three phases are slightly out of phase, our body can feel the handful of mV being leaked.
I've not attempted to charge with only the hot-wire blade extended, but I cannot imagine anything good would happen.
Oh, I remember this! Happened to me when traveling with my Intel-MacBook Pro to South Korea and perhaps some other countries.