I specifically said that the coaches are not infallible. I know they make mistakes. I do believe it's difficult to evaluate how big of a mistake it is they've made without knowing how they came to make the decision they did. It might just be that sometimes what we see as a mistake is actually an effort to cover a glaring weakness that may result in an even worse outcome. I'm not speaking of any specific game here - just coaches and coaching decisions in general.
I tend to believe that the actual professional coaches make fewer mistakes than the Saturday afternoon chatboard heroes would. But go ahead and keep believing that we could pick any random CB'er and have a better record than what we get with the actual coaches currently on staff.*
(*See - I can use hyperbole to completely take what you say out of context too!)