I have a low opinion of medicine in general for the very reason that we hardly know how anything in the body works, and the disclaimer "your results may vary" is very applicable. That said, an expert opinion is better than any wild guess I might come up with, so I'm going to listen.
I'm not up on the news, so I don't know what the comparison is. My understanding is the WHO first advised that masks provide no benefit, then said that it provides some benefit. Even a totally ignorant person would know a mask provides something above zero protection. Then there is the clip above showing Facui change his estimate from 75% to 85% to have effective herd immunity. I'm ignorant of any of the other instances where health officials were either grossly wrong, or otherwise mislead the public.
If my physician admitted that my issue is more complex than previously conveyed, and adjustments were made in response to suboptimal outcomes, I would take more responsibility to educate myself on my own situation, since my health is primarily my responsibility, not someone else's. Based on what I knew would determine my confidence level in my physician. My personal preference is a physician that gets into the nitty gritty details of the science and probabilities, and forgoes the chit-chat altogether; someone whose interest is the science and application of it rather than social relationships. Other patients prefer chit-chat and don't care to know anything about the science, and are happy to blindly follow the advise (or ignore it). They have little interest in "why" to do something, only the "what" to do.
So far I don't see evidence of anyone acting in bad faith, meaning their statements were intended for the benefit of others, possibly with the exception of the WHO advising that mask wearing provides no protection.