Laser printers don't burn the paper. They require toners. So it wasn't a joke unless they also didn't know how a laser printer works.

No he clearly says no ink and no toner. Toner is melted onto the paper after a laser (now mostly LEDs) heat up a drum. He's talking about burning the paper with a laser.... Which would be interesting but really hard to do where a top layer is burned black without toasting the rest of the layers.