Faulty charger teardown

After first use of this charger it exploded, so next day I went to the shop and they replace it by new one. Again, after first use it exploded, so this time I opened it to learn how not to design a charger.

Then I simulated the design with LTSpice but I didn't find anything strange (Files).

So finally I realized that the burned traces are the ones next to the diode so I measured the conductivity on the diode and it gives short circuit in any direction. The conclusion is that a voltage spike made the diode fail to close due to overvoltage.