4th graders are usually aobut 10. I think that the teacher pointed out that there was a mess in the bathroom and when (surprise) some kids started making fun about it, she got upset and made them clean it up.
First, if someone did it on accident, they were probably embarrased by it, and didn’t want to tell the teacher it had happened.
Second, telling annoying kids to clean up poop is probably the stupidest punishment I’ve ever heard of. She should have done something good, like hit them with a book, or make them eat glass.
Third, she’s a damn subsitute. It’s practically the law that kids are supposed to misbehave for a sub. Duh.