there is a difference between clinicians and scientists. most clinicians have never been involved in research and may not be on top of recent research findings. also, they may be more swayed by anecdotal evidence than a scientist who has been subject to the rigors of actually "proving" something. fauci is a scientist and has been involved in research his entire career. he is surely on top of much of the research and would also know which experts in the research community to contact for advice.