Quite an in-depth analysis. Though the human element is still a factor in the following, however, much easier to control, manage and secure, the utilization of independent operating systems in conjunction with independent programs written in specific language (e.g. non-commercial) conducive to the specific type of infrastructure (i.e. power plants in this event) seems like it should have been a common sense approach long ago.
Just a notion I figured was worth mentioning in regards to your post
