Didn't Mufasa break the law by saving Simba from the hyenas?

Wasn't the law that the lions and hyenas never enter each other's territory under any circumstances, and that both sides always have the right to kill any trespasser?

If that is the law, Mufasa clearly broke it, and he definitely shouldn't have. He definitely wouldn't have broken it to save a stranger. He sent a very bad message, which could've caused huge problems. A king should think about the greater good. He at the very least could've handled it better. He threatened the hyenas for following the law he created.

It is hard to blame him though. His son's life was in danger, so he acted without thinking. But they definitely should've addressed it.