I guess it's just very difficult for the doctor if their interpretation of the evidence says that you are ok. They must choose whether to believe their patient, or to trust in their own knowledge and training. In your case, the doctor made the wrong decision and it almost cost you your life. And in other cases people definitely do die due to mistakes made by doctors. ... or at least, the people would not have died if the mistake wasn't make - that doesn't always mean it was the doctor's fault though. People are imperfect - especially when under pressure; and sometimes the strategies that save lives are the same strategies that let other people down.
I'm reminded of a TV series that I enjoyed, called "This is going to hurt".