Interesting video.
I have a Sunko (ebay look alike) hot air station with the same hot air wand as in the video.
When I turn it off after use the fan will operate for a while to cool the tip.
But I noticed that when I turn off the main power to the whole workbench, when I leave for an extended time, on return, when I power up the bench back on the cooling off fan on the Sunko does turn on for a while and then turn off, like in normal use.
That is while the main Sunko front switch is off. That means the unit is still live even when the front panel switch is off, all the time.
I guess a simple line transient could get an SCR (for the heater) full on with no fan, depending on the logic used to control the unit...
Thanks for the video indeed. It should get more visibility.
My unit is getting pulled tonight and will get a real on/off switch hooked to front panel right at the mains right now....