Pulling the power plug => Device damaged
230 V would become 0 V quickly, but that does not mean high currents.  It can, however, mean that the currents right before power was interrupted are maintained for a short while, possibly causing bad voltages as a result.

Yes, this is bad design.  There is no excuse for the device getting damaged because power was interrupted.  Talk to the manufacturer.  If you vaguely hint that you plan to let everyone on the internet know about your experiences with that model, they might be willing to replace it, or give you a discount on the next model up in which this problem has meanwhile been fixed.  Chances are good they know about it.