There’s actually no evidence. The quote you provided was great. It’s as when you debate with a Flat-Earther. It doesn’t matter what you give them as evidence, because they will always believe that it is faulty evidence (lacking or biased).
There actually may not be any way to argue against such logic. It is so blatantly false that we never train for such encounters. We always assume that the individual will be somewhat sane, yet it doesn’t seem like they can be holding beliefs like this.