I have a distinct memory of my mother giving me one strong warning to not touch the glowing burners on the electric stove, then watching while I did so anyway. Then reinforcing the lesson with "what did we learn?" while running cold water on the burn.

This kid seems a little too young to get the right lesson, but sometimes kids are just little assholes who won't really learn boundaries until they experience severe enough negative consequences. It's the parents' job to make sure those negative consequences aren't severe enough to cause permanent trauma.