This is a pretty entertaining story. I'm sure it's not so funny for either the victim or the nurse, but there's a bit of justice that comes with the idea that this woman defended her home successfully.
I wonder about the concept of vengeance. Of course this nurse didn't kill the man out of vengeance, but we readers, on the other hand, like the story because we feel that he got what he deserved. We get our vengeance passively through the resulting circumstance of the nurse fighting back.
Buddhist texts (I think especially in the Pali Cannon) have lots of stories about people paying for their crimes in strange ways. The whole idea of reincarnation is one in which vengeance plays a role--a person who is cold and unfeeling in this life will find vengeance from nature when he is reborn as a cold and unfeeling snake or lizard. Vengeance is not supposed to be good, but it seems to be part of human nature. I wonder if this thirst for vengeance ever goes away. I don't know what I feel about this. Part of me says that vengeance is bad because it fuels hatred, which can create a neverending cycle of tit-for-tat violence and retribution. Another part of me says that it is simply human nature, and that justice cannot exist with some form of vengeance.