It's been a while since I have soldered, so I bought a cheap unbranded soldering iron to use while I re-familiarised myself with the skill. After a few weeks of use, I turned it on just now and it popped with a blue spark. Now it appears to be dead. Did I do something wrong, or is that simply what happens sometimes when you buy a cheap soldering iron? I'm curious to find out what could have happened.

Ironically, I actually bought a new soldering station (Hakko FX-888D) earlier today, not sure why, just had a feeling it was time to get better equipment... spooky.

Out of curiosity, I dismantled the dead soldering iron and took a photo of the board inside.

With my limited knowledge of electronics, my intuition tells me that an arc occurred between the AC wires. If so, is this bad luck, bad soldering, or user error?

The insulation appears burned, but also the core of the wires seems to be a bit frayed. Was this as a result of the arc, or low quality manufacturing?

Bonus question: I wasn't touching the button at the time the iron popped, but if I was, would I have received an electric shock? Would it have been life threatening or painful?

Edit: I am in the UK (230VAC).