It's always interesting to me when people react like this to an internet comment without sharing any research they did themselves.I didn't do any particular research here, because it conflicts with the preexisting knowledge I have about the subject, and because my experience tells me that figures like these, which can be, and especially when they actually are used to further political narrative, are often misleading, and/or wrong. However, I didn't want to accuse the commenter of any bias or misconduct, hence I phrased my question to leave out my skepticism.
The truth of that part isn't important. It's the fact that it's a good faith hint.
You actually hit the spot: you can assume good faith when sitting around in uni and asking people to help you calculate Galois groups. You cannot assume good faith when talking to strangers online on politically charged topics: even if they are themselves operating in good faith, it is highly likely that they were fed, as you call them, "hints", by bad faith actors. Hence, I ask for sources.
I noticed that most people who really know their field don't cite their assertions. It makes sense. So now I'm not surprised when people don't provide a citation.
That's because they can rely on their authority and experience to establish trust, and they have reputation to protect in case their assertions are actually completely wrong. None of this is true when talking to random, anonymous people online.