"Self-righteousness" is an unfalsifiable accusation. When someone is accused of being self-righteous, if they defend themselves, then they are self-righteous because they believe they are right and good; if they don't defend themselves, they accept the accusation of self-righteousness.

Similarly, "You just refuse to admit you were wrong." No matter how you respond, it reinforces the other party's accusation. In logic, this is called a "Kafkatrap": denying the accusation itself is treated as evidence that the accusation is valid.

Those who see through the magic trick will not be deceived by the magic.