Might just be but that struck me as a person that googled a sheet on how to get picky rat snakes or king snakes to eat. They will give a reaction bite after a while and realize food, I wander if that person was trying to go this way despite hognose snakes not deliberately biting out of self defense.

Usually putting the food in a secure spot where the snake will feel safe works better than that method, and if substrate is worrisome to the keep, the keeper could use a paper towel and remove it later when the snake has eaten and moved on.