Firstly, the toupee fallacy: all toupees look fake. You may be able to spot all bad toupees but the good ones fly under your radar and thus you can’t ever know how good you’re actually at spotting them.
Also the assumption-as-fact bias. You think a story is false but did you ever get confirmation that you were right or are you treating your assumption as a fact?
Two things to keep in mind here.
Firstly, the toupee fallacy: all toupees look fake. You may be able to spot all bad toupees but the good ones fly under your radar and thus you can’t ever know how good you’re actually at spotting them.
Also the assumption-as-fact bias. You think a story is false but did you ever get confirmation that you were right or are you treating your assumption as a fact?