This type of circular sourcing is very common in the news these days
Yes, I observed that, too. Indeed, that is what people do also in the private realm.
While I think, the question "where do you know it from?" may be not the best question at all. Instead of asking for the sources, one could ask differently. Like "How do you think this phenomena can be explained in your own terms?" or even not referring to the event itself but questions which point more to the inner life of a human. I can't come up with a proper scenario, for it would be too theoretical. I only remember the questions I asked a friend: "Do you think you have to be coerced to behave?" and "Imagine all people were of the same notion. Is that imaginable or even possible?"
All the best for you in your new destination.