Ok, first of all, I think you handled it well. The worst thing you could have done was instinctively say something like "nu uh!! that sounds like western propaganda!" and then be completely proven wrong and forever lose credibility in that lib's (hopefully future leftist's) eyes.
Second, know your shit at least. It's pretty well known that Xi himself traveled to the US as young man. He has ties to some Iowa town or something. (https://www.nytimes.com/2012/02/16/world/asia/xi-jinping-of-china-makes-a-return-trip-to-iowa.html)
Third, if someone ever brings that dumb shit about his daughter up again, just mention how Tim Walz taught English in China and basically loves China (though he has super lib views on Tienanmen, Tibet, "organ harvesting", etc.). (https://www.nytimes.com/2024/08/11/us/tim-walz-china.html)
Yeah but hasn't the history of scientific progress shown that every time we think we're at a stagnation point, a breakthrough discovery is made that shatters the old paradigm?