I have great respect for many of our sages of blessed memory, but there seems to be a tendency among Jews to refuse to admit the possibility that they could have ever made mistakes. I have been grappling with this question as I was trying unsuccessfully to write an answer to a this recent question. It is extremely hard to speak of the fallibility of our sages in a socially acceptable way.
One way to see this is to look at some of the reasoning on why we no longer follow Talmudic medicine. You often find something along the lines of the reasons given by the Maharil, that the descriptions are unclear, that we cannot understand what they mean, that if we tried it and did it wrong one might come to belittle the sages.
I almost never see an orthodox rabbi say: they were men who worked with the knowledge that was available at the time. They tried to apply Jewish principles to the world as they understood it, but they may have been mistaken in specific facts about the world.
The notion that any human could be infallible bothers me. I would gladly agree that Chazal were righteous, intelligent people with much integrity. I would also agree that is not good for people like us who have lesser moral qualities to criticize those who are greater than us, but does this mean that it is wrong to make respectful observations that such-and-such person was wrong about one particular issue that we can now understand in a completely different way? So they didn't know anything about germ theory or which creatures were real and which were mythical. Why is that so bad to say? Why do we tie ourselves in knots to avoid saying that they could be wrong occasionally?