A teacher was too nice, lost control of her class and then slapped one of them. Another teacher is trying to comfort her:
Because I also spoil them too much the children learnt a lesson, didn't they?
I always get confused with endings like んじゃないでしょうか. My translation makes no sense. I assume he is saying that the kids didn't learn a lesson because he spoils them too much, but I don't see how this can mean that they didn't learn a lesson.
What is the actual meaning of this sentence and how do I parse it correctly?