I'm a physician. Do you know how often I'm wrong on my initial opinion? Often, but as all physicians are trained to do, including Dr. Fauci, we continually evaluate and reassess new information as it presents. Diseases and patients don't follow a predefined set of instructions when the get sick, otherwise, medicine would simply be like following a cookbook. We leave open the possibility that our initial impression might be wrong, that's why we mentally formulate a differential diagnosis and have alternative testing and treatments lined up if the initial lead doesn't pan out.
That's how medicine works, both on the individual and the macro level. Most people on here seem to understand that except you. Or can you just not let it die because you don't like masks?