I apologize for not scouring the internet for examples. If you had not sought those examples out and provided them, I probably would have never seen any cases of incorrect fact-checking in my actual life, but I would have seen many cases of misinformation being fact-checked. If you have to intentionally find such cases or hear them shouted from the rooftops by free speech advocates, then they probably aren't that many such cases.

I don't have time to search through an entire Youtube channel, but I will say this: there are many, many doctors out there with factually incorrect views about medical science. I personally have talked with doctors who think that the Covid vaccine killed hundreds of thousands of people (it didn't). I do not necessarily think this doctor is wrong, but from the perspective of a fact-checker who is given the current best knowledge of Covid it is hard to determine who is making genuine good-faith efforts to criticize vs who is simply repeating what they want to be true.

And for the record, you absolutely are allowed to criticize the establishment views. When it comes to important topics like medical science, however, you may just have additional context added saying that this is a contrarian view which (statistically) is more likely to be false than the consensus. Everybody likes to complain loudly about being censored, but the reality is that their views are just being disputed and information provided that they are going against the mainstream view.