Caleb,
I like the way you summarized in the first paragraph “small oversights”. That is paramount in my opinion to network safety. There are so many steps to take to ensure you are doing everything you can, and even then someone may still “crack the network”. So taking every precaution we can to ensure we are using every tool at our disposal is so important.
I also really liked your ending statement. All we can do is be prepared. However, I also believe that remembering your first plan will eventually fail. So what do we do when something does go wrong? Is just as important.