"“I did, and as I turned around, I realised he was covered in black toner powder from the neck up… I don't know how he did it but he managed to pry open the toner cartridge and blasted toner into his face. He thought the powder went into the printer.”"
This reminds me of a quite recent story.
Small office, single printer, and of course, the recycling cartridge was full. And no, the office manager had only planned for *toner* cartridges, not recycling cartridge.
So, not being an expert, I pointed out to her we need to dispose properly of this full cartridge (it was even written in big red letters "don't throw away in the wild") via the support contract.
But she would have none of it and explained we will dispose "the usual way" and proceeded to show me.
She would go to the men room (yes, men, not women), and dump the whole content in the sink (fumes everywhere) and proceed to flush all out.
I was like, speechless.