This shit has seriously gone on too long. People who continue to cling to the "10,000 dead crushed by tanks hosed i to the gutter" bs are cranks. It's jews control the banks, chemtrails, the earth is flat, the moon isn't real level of crank shit and unless you're feeling very indulgent and someone is asking in good faith it can be dismissed as equally serious to that kind of crank shit.
If I had to take a guess based on my own past as a dumbass radlib who believed anti China bullshit I'd say he's trying to claim that by not listening to Chinese people who claim it happened we're ignoring their voices and that makes us racist against Chinese people even though he's the one who actually hates China
See in his mind he thinks every single Chinese person who knows it didn't happen is brainwashed and they just don't know the truth so it's OK for him to not listen to any of them, also he believes that it's physically impossible for him to be racist by virtue of being a liberal
So yeah, very tangled mess of brainworms but I think I sorted them out
I can't believe I used to think like this and consider myself smart for it
There's a legit thing where "smart" people can be more susceptible to confirmation bias because they're skilled at finding patterns in information, but that doesn't mean the pattern is necessary real or significant. "Intelligence" (i am skeptical of the concept of a single intelligence trait) doesn't necessarily protect you from weird cognitive stuff.
And the gotcha libs are like "i ran up to a random person in Beijing, shoved a microphone in their face, and started interogating them about 20th century politics! They got uncomfortable and left! That proves [fascist screeching]