I did not even call the claim false, even if it almost deserve it...I said, essentially ...let's see the references so we can treat this as fact rather than opinion.
What you did is write a longer and more prescriptive comment about my tone than anything anyone has written about the actual substance :-)). You tone policed a one line request for evidence while giving a complete pass to unsourced medical statistics presented as fact.
If we are ranking things that erode discourse quality, I would say you are higher on the list.
It's one thing to talk casually, in which case I agree with you. But as soon as hard numbers are on the table, it's no longer casual, and if you do not provide sources then the assumption has to be that you pulled the numbers out of your ass and you are not to be trusted.
To get around that, just don't provide numbers and don't speak authoritatively. It's very easy, I don't know why people speak authoritatively if they know they can't back it up.
"SOURCE?"
There's a middle ground here that is a grey area that you seem to be pretending is obviously navigated. You're speaking pretty authoritatively on this by the way. Do you have the moral, propositional logic, and epistemological justification for these claims?
If someone was making an important calculation or decision based on the circumference of the earth, then they would likely want the number cited/confirmed and not just thrown out by a random person that doesn’t pass the smell test. “Radiologists are only right 35% of the time” does not pass the smell test and a cursory search makes the case even worse.
And there's obviously a difference between an established and obvious fact and a BOLD claim. This person made a BOLD claim. And provided numbers. To me, that requires a source.
Yes, there is a middle ground, but this isn't in the middle ground. I think this type of claim requires a source. A different claim, without specific percentages, would not. Or an obvious claim, like the Earth's circumference, also would not.